Adept three-dimensional printing

ABSTRACT

The present disclosure provides three-dimensional (3D) printing methods, apparatuses, systems, and non-transitory computer-readable medium. The disclosure delineates real time manipulation of three-dimensional printing to reduce deformation. The present disclosure further provides 3D object formed using the methods, apparatuses, and systems.

CROSS-REFERENCE

This application claim priority to U.S. Provisional Patent ApplicationSer. No. 62/252,330 that was filed on 6 Nov. 2015, and U.S. ProvisionalPatent Application Ser. No. 62/396,584 that was filed on 19 Sep. 2016;each of which is entirely incorporated herein by reference.

BACKGROUND

Three-dimensional (3D) printing (e.g., additive manufacturing) is aprocess for making a three-dimensional (3D) object of any shape from adesign. The design may be in the form of a data source such as anelectronic data source, or may be in the form of a hard copy. The hardcopy may be a two-dimensional representation of a 3D object. The datasource may be an electronic 3D model. 3D printing may use an additiveprocess in which successive layers of material are laid down one on topof each other. This process may be controlled (e.g., automaticallyand/or manually controlled). A 3D printer can be an industrial robot.

3D printing can generate custom parts quickly and efficiently. A varietyof materials can be used in a 3D printing process including elementalmetal, metal alloy, ceramic, elemental carbon, and/or polymericmaterial. In a typical additive 3D printing process, a firstmaterial-layer is formed, and thereafter, successive material-layers (orparts thereof) are added one by one, wherein each new material-layer isadded on (e.g., and connected to) a pre-formed material-layer, until theentire designed three-dimensional structure (3D object) is materialized.

3D models may be created utilizing a computer aided design packageand/or via 3D scanner. The manual modeling process of preparinggeometric data for 3D computer graphics may be similar to plastic arts,such as sculpting or animating. 3D scanning is a process of analyzingand collecting digital data on the shape and appearance of a realobject. Based on this data, 3D models of the scanned object can beproduced. The 3D models may include computer-aided design (CAD).

A large number of additive processes are currently available. They maydiffer in the manner layers are deposited to create the materializedstructure. They may vary in the material or materials that are used togenerate the designed structure. Some methods melt or soften material toproduce the layers.

SUMMARY

At times, the printed three-dimensional (3D) object may bend, warp,roll, curl, or otherwise deform during and/or after the 3D printingprocess. Some formations may accumulate during the 3D printing. Forexample, some deformations may comprise accumulative residualdeformation. Some deformations are particularly prevalent when the firstone or more of layers is 3D printed (e.g., up to a total thickness offrom about one (1) millimeters to about two (2) millimeters). In someembodiments, the following disclosure proposes ways to reduce a degreeof the deformation. The degree reduction of the deformation may comprisea 3D printing methodology that comprises using: (i) a real time control(e.g., of the temperature in the material bed, energy beam power, and/orheight of the printed 3D part), (ii) object pre-print correction, (iii)at least one cooling mechanism, or (iv) any combination thereof. In someembodiments, the real time control during the 3D printing is achievedusing fast, efficient, and/or parallel processing.

Auxiliary supports may be inserted to reduce the deformation. Theseauxiliary supports may be removed from the printed 3D object after the3D printing, to produce a desired 3D product (e.g., 3D object). In someembodiments, the present disclosure illustrates generation of 3D objectswith reduced degree of deformation. In some embodiments, these 3Dobjects are fabricated with diminished number (e.g., absence) ofauxiliary supports.

In an aspect, the present disclosure delineates methods, systems,apparatuses, and software that facilitate materialization of 3D objectswith a reduced amount of design constraints (e.g., no designconstraints).

In some instances, it is desired to control (e.g., in real time) themanner in which at least a portion of a layer of hardened material(e.g., as part of the 3D object) is formed. For example, it may bedesired to control the manner, type, direction, and/or degree ofdeformation of at least a layer portion of the 3D object. For example,it may be desired to control a deformation of at least a surface of the3D object.

In some instances, in order to achieve the desired 3D object, it may bedesired to control the 3D object during its formation (e.g., in realtime). For example, it may be desired to control the formation of the 3Dobject using open loop and/or closed loop control. For example, it maybe desired to control the formation of the 3D object using feed forwardand/or feedback control. In various embodiments, the present disclosuredelineates detection, and control of at least the deformations disclosedherein using at least one of the control methodologies disclosed herein.

In another aspect, a method for forming a 3D object comprises: (a)transforming a portion of a material bed with an energy beam to form atleast a portion of the 3D object; and (b) controlling in real time atleast one characteristics of the energy beam with a controllercomprising a control-model related that is related to a requested 3Dobject. The controller may comprise an electronic circuit. In someexamples, related to comprises geometric (e.g., shape and/or layers) ormaterial properties of the requested three-dimensional object.

The control-model may comprise information relating to a slice of therequested 3D object. The control-model may comprise astate-observer-model. The control-model can be adjusted in real timeduring the forming of the 3D object. The control-model can be configuredto the controller. The control-model can be wired to the controller.Real time may be during a dwell time of the energy beam along a hatchline forming a melt pool. The controlling can use a processor comprisingat least 3 Tera floating point operations per second, according to abenchmark. The method may further comprises adjusting the at least onecharacteristics of the energy beam and repeating (a) to (b). The closedloop control may use at least one threshold value. The control-model cancomprise a simulation. The simulation can comprise a temperature ormechanical simulation of the 3D printing. The simulation can comprise athermo-mechanical simulation. The simulation can comprise a materialproperty of the 3D object. The simulation can comprise a geometry of the3D object. The control-model can be dynamically adjusted in the realtime. The control-model can comprise a simplified model relative to therequested model of the 3D object. The 3D object can be substantiallysimilar to the requested 3D object. Substantially can be relative to theintended purpose of the 3D object. The 3D object may deviate from arequested 3D object by at most about 100 micrometers.

In another aspect, a system for forming at least one 3D objectcomprises: (a) an energy beam that transforms at least a portion of amaterial bed to a transformed material; and (b) a controller comprisinga control-model that is related to a requested 3D object, whichcontroller is operative coupled to the energy beam and is programmed todirect the energy beam to transform the at least a portion of thematerial bed to form the at least one 3D object using the control-model.

The control-model can be adjusted in real time during the forming of theat least one 3D object. Real time is during a dwell time of the energybeam along a hatch line forming a melt pool. The control-model can beconfigured to the controller. The control-model can be wired to thecontroller. The parameter can comprise a temperature, height, or powerdensity. At least one 3D object can be a plurality of 3D objects. Theplurality of 3D objects can be formed in the same material bed. Theplurality of 3D objects can be formed in parallel. The plurality of 3Dobjects can be formed sequentially. The controller can comprise a closedloop or open loop control. The controller can comprise a feedback orfeed-forward control. The controller can comprise a simulation. Thesimulation can comprise a temperature or mechanical simulation of the 3Dprinting. The simulation may comprise thermo-mechanical simulation. Thesimulation can comprise a material property of the requested 3D object.The mechanical simulation can comprise elastic or plastic simulation.The controller can comprise a graphical processing unit (GPU),system-on-chip (SOC), application specific integrated circuit (ASIC),application specific instruction-set processor (ASIPs), programmablelogic device (PLD), or field programmable gate array (FPGA).

In another aspect, an apparatus for forming at least one 3D objectcomprises: (a) an energy source generating an energy beam thattransforms at least a portion of a material bed to a transformedmaterial; and (b) a controller comprising a control-model that isrelated to a requested 3D object, which controller is operative coupledto the energy beam and is programmed to direct the energy beam totransform the at least a portion of the material bed to form the atleast one 3D object using the control-model. The control-model can beconfigured to the controller. The control-model can be wired to thecontroller.

In another aspect, an apparatus for forming at least one 3D objectcomprises (a) a first controller that directs an energy beam totransform at least a portion of a material bed to form the at least one3D object, which first controller is operatively coupled to the energybeam; and (b) a second controller comprising a control-model that isrelated to a requested 3D object, which second controller alters atleast one characteristics of the energy beam in real time using thecontrol-model, wherein the second controller is operatively coupled tothe energy beam and to the first controller.

The first controller and the second controller may be the samecontroller. The first controller and the second controller may bedifferent controllers. Real time can be during the forming of the 3Dobject. For example, during forming of a layer of the 3D object. Forexample, during a dwell time of the energy beam along: (i) a path, or(ii) a hatch line forming a melt pool. The control-model may comprise asimulation. The control-model may relate to a simplified model of the 3Dobject. The control-model may comprise a simplified model of the 3Dobject. The altered model can be configured to the controller. Thealtered model can be wired to the controller.

In another aspect, a computer software product for 3D printing of atleast one 3D object comprises a non-transitory computer-readable mediumin which program instructions are stored, which instructions, when readby a computer, cause the computer to perform operations comprising: (a)direct an energy beam to transform at least a portion of a material bedto form the at least one 3D object; and (c) direct at least onecontroller that comprises a control-model that is related to a requested3D object, to control in real time at least one characteristics of theenergy beam using the altered model. The altered model can be configuredto the controller. The altered model can be wired to the controller.

In another aspect, a method for forming a 3D object comprises: (a)transforming a portion of a material bed with an energy beam to form aportion of the 3D object; (b) measuring a parameter at one or morelocations of the material bed; and (c) controlling in real time at leastone characteristics of the energy beam with a closed loop control byusing the measured parameter, wherein real time is during a dwell timeof the energy beam along: (i) a path, or (ii) a hatch line forming amelt pool.

Real time can be during a dwell time of the energy beam along a hatchline forming a melt pool. The controlling can utilize a processorcomprising at least 3 Tera floating point operations per second,according to a benchmark. The parameter can comprise a temperature,height, or power density. The at least one characteristics can comprisea power per unit area, trajectory, dwell time, footprint, cross section,or focus. The controlling can comprise altering. The method can furthercomprise altering the at least one characteristics of the energy beamand repeating operations (a) to (c). The closed loop control may use oneor more target parameters comprising temperature, metrology, or powerper unit area. The closed loop control may utilize at least onethreshold value. The closed loop control may utilize a control-modelcomprising a simulation. The simulation can comprise a temperature ormechanical simulation of the 3D printing. The simulation can comprise amaterial property of the 3D object. The simulation can comprise ageometry of the 3D object. The control-model can be dynamically adjustedin the real time. The control-model can comprise a simplified modelrelative to a requested model of the 3D object. The 3D object maydeviate from a requested 3D object by at most about 100 micrometers. Theone or more locations of the material bed can comprise one or morelocations of the 3D object during its formation.

In another aspect, a system for forming at least one 3D objectcomprises: (a) an energy beam that transforms at least a portion of amaterial bed to a transformed material; (b) one or more sensorsmeasuring a parameter of one or more locations in the material bed; and(c) at least one controller comprising a closed loop control, which atleast one controller is operative coupled to the energy beam and to theone or more sensors and is programmed to: (i) direct the energy beam totransform the at least a portion of the material bed to form the atleast one 3D object; (ii) direct the one or more sensors to measure oneor more parameters of one or more locations on at least a portion of theat least one 3D object; and (iii) control in real time at least onecharacteristics of the energy beam using the measured one or moreparameters, wherein real time is during a dwell time of the energy beamalong: (1) a path, or (2) a hatch line forming a melt pool.

At least two of operations (i) to (iii) are controlled by the samecontroller. The at least one controller can be a multiplicity ofcontrollers. At least two of operations (i) to (iii) are controlled bythe multiplicity of controllers respectively, which multiplicity ofcontrollers are operatively coupled. The at least one 3D object can be aplurality of 3D objects. The plurality of 3D objects can be formed inthe same material bed. The plurality of 3D objects can be formed inparallel. The plurality of 3D objects can be formed sequentially. Theone or more locations of the material bed can comprise one or morelocations of the at least one 3D object during its formation.

In another aspect, an apparatus for forming at least one 3D objectcomprises at least one controller that is programmed to: (a) direct anenergy beam to transform at least a portion of a material bed to formthe at least one 3D object; (b) direct one or more sensors to measureone or more parameters of one or more locations of the material bed; and(c) control in real time at least one characteristics of the energy beamusing the measured one or more parameters, wherein real time is during adwell time of the energy beam along (i) a path, or (ii) a hatch lineforming a melt pool.

At least two of operations (a) to (c) can be controlled by the samecontroller. The at least one controller can be a multiplicity ofcontrollers. At least two of operations (a) to (c) can be controlled bytwo different controllers respectively. The one or more sensors canmeasure the one or more parameters respectively. The one or morelocations of the material bed may comprise one or more locations of theat least one 3D object during its formation.

In another aspect, an apparatus for forming a 3D object comprises: (a)an energy beam that transforms at least a portion of a material bed toform at least a portion of the 3D object; (b) one or more sensors thatmeasure one or more parameters of one or more locations of the materialbed, which one or more sensors are disposed adjacent to the materialbed; and (c) a controller that controls in real time at least onecharacteristics of the energy beam based on the measured one or moreparameters, wherein real time is during a dwell time of the energy beamalong: (i) a path, or (ii) a hatch line forming a melt pool, whichcontroller is operatively coupled to the energy beam and to the one ormore sensors.

In another aspect, a computer software product for 3D printing of atleast one 3D object comprises a non-transitory computer-readable mediumin which program instructions are stored, which instructions, when readby a computer, cause the computer to perform operations comprising: (a)direct an energy beam to transform at least a portion of a material bedto form the at least one 3D object; (b) direct one or more sensors tomeasure one or more parameters of one or more locations of the materialbed; and (c) direct at least one controller to control in real time atleast one characteristics of the energy beam using the measured one ormore parameters, wherein real time is during a dwell time of the energybeam along: (i) a path, or (ii) a hatch line forming a melt pool.

In another aspect, a method for forming a 3D object comprises: (a)altering a 3D model of a requested 3D object to form an altered model,which altering comprises a structural alteration, wherein at least afirst derivative of the difference between (i) the altered model and(ii) the 3D model that is related to the requested 3D object, iscontinuous; and (b) transforming at least a portion of a material bedwith an energy beam according to the altered model to form the 3Dobject, wherein the 3D object is substantially similar to the requested3D object.

The transforming can comprise dynamically adjusting the altered model inreal time the formation of the 3D object. The method may furthercomprise after operation (a) and before operation (b): generating aprinting instruction by using the altered model. Transforming at least aportion of a material bed with an energy beam in operation (b) may beaccording to the printing instruction. The generation of the printinginstruction can comprise dynamically adjusting the altered model in realtime during the transformation of the at least a portion of the materialbed. The dynamically adjusting can comprise using a closed loop control.The dynamically adjusting can comprise using a real time measurement ofone or more sensors. The generation of the printing instruction cancomprise using a simulation comprising thermal, mechanical, geometric,or material properties of the 3D object (or a portion thereof). Thegeneration of the printing instruction can comprise using a simulationcomprising thermal, mechanical, geometric, or material properties of the3D model of the requested 3D object (or a portion thereof). Generatingthe printing instruction can comprise using a geometric informationderiving from a previously formed portion of the three-dimensionalobject. The geometric information can comprise a local thickness below agiven layer, local build angle, proximity to an edge on a given layer,or proximity to layer boundary. The simulation can be dynamicallyadjusted in real time during the formation of the three-dimensionalobject (e.g., during a layer thereof, an energy beam path, or a hatchforming at least one melt pool). The substantially similar can berelative to the intended purpose of the 3D object. The 3D object maydeviate from the model of the 3D object by at most about 100micrometers. The at least the first derivative may be a plurality ofderivatives. For example, the plurality of derivatives can comprise thefirst three derivatives. The 3D model of the requested 3D object maycomprise slices. The altering may comprise a structural adjustment of aplurality of the slices. The 3D object may comprise layers. The slicesmay correspond to layers in the 3D object (e.g., respectively). The 3Dobject may be formed by additive manufacturing.

In another aspect, a system for forming at least one 3D objectcomprises: (a) an energy beam that transforms at least a portion of amaterial bed to a transformed material; (b) a first processor thatalters a 3D model of a requested 3D object to an altered model, whichaltered model comprises a structural alteration, wherein at least afirst derivative of the difference between (i) the altered model and(ii) the 3D model of the requested 3D object, is continuous; and (c) atleast one controller that is operative coupled to the energy beam and tothe second processor and is programmed to: direct the energy beam totransform at least a portion of a material bed according to the alteredmodel to form the 3D object, wherein the 3D object is substantiallysimilar to the requested 3D object.

The system may further comprise a second processor that generates aprinting instruction using the altered model. The second processor maybe operatively coupled to the first processor. Transformation of the atleast a portion of a material bed may be according to the printinginstruction. The first processor and the second processor may bedifferent. The first processor and the second processor may be the sameprocessor. The material bed can comprise a powder material. The powdermaterial can be flowable during the forming of the at least one 3Dobject. The powder material in the powder bed can be unfixed during theforming of the at least one 3D object. The material bed can be can be atambient pressure during the forming of the at least one 3D object. Thematerial bed can be at ambient temperature during the forming of the atleast one 3D object. The material bed can include a powder bedcomprising individual (e.g., solid) particles formed of at least onemember selected from the group consisting of an elemental metal, metalalloy, ceramic, and an allotrope of elemental carbon. Transforming cancomprise melting or sintering. Melting can comprise complete melting.The energy beam can comprise an electromagnetic or charged particlebeam. The energy beam can comprise a laser or an electron gun. Thecontroller can comprise closed loop control or open loop control. Thecontroller can comprise feedback control or feed-forward control. Thecontroller can comprise parallel processing. The parallel processing cancomprise a graphical processing unit (GPU), system-on-chip (SOC),application specific integrated circuit (ASIC), application specificinstruction-set processor (ASIPs), programmable logic device (PLD), orfield programmable gate array (FPGA). The controller can use a thresholdvalue for the direct. The controller can use a sensor input for thedirect.

In another aspect, an apparatus for generating a 3D object comprises acontroller that is programmed to direct an energy beam to transform atleast a portion of a material bed according to an altered model of arequested 3D object to generate the 3D object, which altered modelcomprises a structural (e.g., geometric) alteration of a 3D model of therequested 3D object, wherein at least a first derivative of thedifference between (i) the altered model and (ii) the 3D model of therequested 3D object, is continuous, and wherein the 3D object issubstantially similar to the requested 3D object. The transformation ofat least a portion of a material bed may be according to a printinginstruction, which printing instruction uses the altered model.

In another aspect, an apparatus for forming a 3D object comprises: (a) afirst processor that alters a 3D model of a requested 3D object to analtered model, which altered model comprises a structural (e.g.,geometric) alteration, wherein at least a first derivative of thedifference between (i) the altered model and (ii) the 3D model of therequested 3D object, is continuous; and (b) an energy beam thattransforms at least a portion of a material bed to a transformedmaterial as part of the 3D object according to the altered model,wherein the 3D object is substantially similar to the requested 3Dobject. The apparatus may further comprise a second processor thatgenerates a printing instruction using the altered model. The energybeam may be operatively coupled to the second processor. The firstprocessor may be operatively coupled to the second processor. The firstprocessor and the second processor can be different. The first processorand the second processor can be the same processor. The transformationof at least the portion of the material bed may be according to theprinting instruction that is related to (e.g., comprises) the alteredmodel. In some examples, related to comprises geometric (e.g., shapeand/or layers) or material properties of the requested three-dimensionalobject.

In another aspect, a computer software product for 3D printing of atleast one 3D object comprises a non-transitory computer-readable mediumin which program instructions are stored, which instructions, when readby at least one computer, cause the at last one computer to performoperations comprising: (a) alter a 3D model of a requested 3D object toan altered model, which altered model comprises a structural (e.g.,geometric) alteration, wherein at least a first derivative of thedifference between (i) the altered model and (ii) the 3D model of therequested 3D object, is continuous; and (b) direct an energy beam totransform at least a portion of a material bed to form the 3D objectaccording to the altered model, wherein the 3D object is substantiallysimilar to the requested 3D object. The operation may further comprise(c) generate a printing instruction using the altered model. Theoperation (c) may take place after (a) and before (b). Thetransformation of the at least the portion of the material bed may beaccording to the printing instruction. The printing instruction mayrelate to the altered model. The printing instruction may comprise thealtered model. At least two of operations (a) to (c) can be performed bythe same computer. The at least one computer can be a multiplicity ofcomputers. At least two of operations (a) to (c) can be performed by themultiplicity of computers (e.g., respectively). The multiplicity ofcomputers may be operatively coupled.

In another aspect, a system for forming at least one 3D objectcomprises: (a) an energy beam that transforms at least a portion of amaterial bed to a transformed material; (b) a first processor thatalters a 3D model of a requested 3D object to an altered model, whichaltered model comprises a structural adjustment, wherein the 3D model ofthe requested 3D object comprises slices, which altered model comprisesa structural adjustment of a plurality of the slices; (c) a secondprocessor that generates a printing instruction using the altered model,wherein the second processor is operatively coupled to the firstprocessor; and (d) at least one controller that is operative coupled tothe energy beam and to the second processor and is programmed to: directthe energy beam to transform at least a portion of a material bedaccording to the printing instruction to form the 3D object, wherein the3D object is substantially similar to the requested 3D object.

The first processor and the second processor can be different. The firstprocessor and the second processor can be the same processor. Thematerial bed can comprise a powder material. The powder material can beflowable during the forming of the at least one 3D object. The materialin the material bed (e.g., powder material) can be unfixed during theforming of the at least one 3D object. The material bed can be atambient pressure during the forming of the at least one 3D object. Thematerial bed can be at ambient temperature during the forming of the atleast one 3D object. The material bed can comprise a powder bedcomprises individual particles formed of at least one member selectedfrom the group consisting of an elemental metal, metal alloy, ceramic,and an allotrope of elemental carbon. Transforming can comprise meltingor sintering. Melting can comprise complete melting. The energy beam cancomprise an electromagnetic or charged particle beam. The energy beamcan comprise a laser or an electron gun. The controller can compriseclosed loop control or open loop control. The controller can comprisefeedback control or feed-forward control. The controller can compriseparallel processing. The parallel processing can comprise a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA). The controller can use a threshold valuefor the direct. The controller can use a sensor input for the direct.

In another aspect, an apparatus for generating a 3D object comprises acontroller that is programmed to direct an energy beam to transform atleast a portion of a material bed according to a printing instruction togenerate the 3D object, which printing instruction uses an altered modelof a requested 3D object, which altered model comprises a structuralalteration of the 3D model of the requested 3D object, wherein the 3Dmodel of the requested 3D object comprises slices, which altered modelcomprises a structural adjustment of a plurality of the slices, andwherein the 3D object is substantially similar to the requested 3Dobject.

In another aspect, an apparatus for forming a 3D object comprises: (a) afirst processor that alters a 3D model of a requested 3D object to analtered model, which altered model comprises a structural alteration,wherein the 3D model of the requested 3D object comprises slices, whichaltered model comprises a structural alteration of a plurality of theslices; (b) a second processor that generates a printing instructionusing the altered model, wherein the energy beam is operatively coupledto the second processor, wherein the first processor is operativelycoupled to the second processor; and (c) an energy beam that transformsat least a portion of a material bed to a transformed material as partof the 3D object according to the printing instruction, wherein the 3Dobject is substantially similar to the requested 3D object. The firstprocessor and the second processor can be different. The first processorand the second processor can be the same processor.

In another aspect, a computer software product for 3D printing of atleast one 3D object, comprises a non-transitory computer-readable mediumin which program instructions are stored, which instructions, when readby at least one computer, cause the at last one computer to performoperations comprising: (a) alter a 3D model of a requested 3D object toan altered model, which altered model comprises a structural alteration,wherein the 3D model of the requested 3D object comprises slices, whichaltered model comprises a structural adjustment of a plurality of theslices; (b) generate a printing instruction using the altered model; and(c) direct an energy beam to transform at least a portion of a materialbed to form the 3D object according to the printing instruction, whereinthe 3D object is substantially similar to the requested 3D object. Atleast two of (a) to (c) can be performed by the same computer. The atleast one computer can be a multiplicity of computers. At least two of(a) to (c) can be performed by the multiplicity of computersrespectively, wherein the multiplicity of computers is operativelycoupled.

In another aspect, a method for forming a 3D object comprises: (a)transforming at least a portion of a material bed with an energy beam,wherein the material bed is disposed in an enclosure; (b) cooling thematerial bed during the transforming with a first cooling member that ismobile during the forming of the three-dimensional object, wherein thefirst cooling member is disposed in the enclosure, wherein the firstcooling member is separated from the exposed surface of the material bedby a gap comprising a gas, wherein the first cooling member comprises aheat conductive material; and (c) cooling the first cooling member witha second cooling member that is disposed (i) at an enclosure wall or(ii) outside of the enclosure, wherein the second cooling member isstationary, wherein the second cooling member comprises an opening.

During the forming of the three-dimensional object can comprise duringthe transforming of the at least a portion of the material bed. Thecooling can comprise a physical contact. The physical contact can be adirect physical conduct between the first cooling member and the secondcooling member. The physical contact can be an indirect physical conductbetween the first cooling member and the second cooling member. Thesecond cooling member can comprise active cooling using a coolant. Thecoolant may travel through the second cooling member during the coolingin (c). The second cooling member can comprise an exit opening and anentrance opening. The second cooling member can comprise active coolingusing a coolant that enters though the entrance opening and exits thoughthe exit opening. The first cooling member can comprise a heat sink. Thesecond cooling member can comprise a heat exchanger. The heat conductivematerial can be at least about 20 Watts per meter times degrees Kelvin(W/mK), as measured at an ambient temperature. The first cooling memberand the second cooling members may be disposed in different atmospheres.The first cooling member can be disposed at an inert atmosphere. Thesecond cooling member can be disposed at an ambient atmosphere. Thefirst cooling member may follow the energy beam during the forming ofthe three-dimensional object (e.g., during the transforming). Themovement of the first cooling member may be synchronized with themovement of the energy beam during the forming of the three-dimensionalobject (e.g., during the transforming). The first cooling member cancomprise an opening to let the energy beam travel though. The firstcooling member can be disposed along a trajectory of the energy beam tothe material bed. The method may further comprise cooling the materialbed during the forming of the three-dimensional object (e.g., during thetransforming) with a third cooling member. The third cooling member canbe mobile during the forming of the three-dimensional object (e.g.,during the transforming). The third cooling member can be disposed inthe enclosure. The third cooling member can be separated from theexposed surface of the material bed by a gap comprising a gas. The thirdcooling member can comprise a heat conductive material. The heatconductive material can be at least about 20 Watts per meter timesdegrees Kelvin (W/mK), as measured at an ambient temperature. The thirdcooling member can be passive. The third cooling member can comprise aheat sink. The third cooling member can comprise a heat sink. The methodmay further comprise cooling the third cooling member with the secondcooling member. Cooling of the third cooling member with the secondcooling member can comprise a physical contact. The physical contact canbe a direct physical conduct between the third cooling member and thesecond cooling member. The physical contact can be an indirect physicalconduct between the third cooling member and the second cooling member.

In another aspect, a system for forming a 3D object comprises: (a) amaterial bed disposed in an enclosure; (b) an energy source generatingan energy beam that transforms at least a portion of the material bed,wherein the energy source is disposed adjacent to the enclosure; (c) afirst cooling member comprising a heat conductive material, which firstcooling member is separated from the material bed by a gap comprising agas, which first cooling member is mobile, wherein the first coolingmember is disposed in the enclosure; (d) a second cooling membercomprising an opening, which second cooling member is stationary,wherein the second cooling member is disposed at a wall of the enclosureor outside of the enclosure; and (e) at least one controller that isoperatively coupled to the energy beam, the first cooling member, andthe second cooling member, and is programmed to (i) direct the energybeam to transform at least a portion of the material bed to form the 3Dobject, (ii) direct the first cooling member to cool the material bedwhile moving during the forming of the three-dimensional object, and(iii) direct the first cooling member to exchange heat with the secondcooling member during formation of the 3D object.

During the forming of the three-dimensional object can comprise duringthe transformation of the at least a portion of the material bed to formthe 3D object (e.g., during operation (i)). The first cooling member canexchange heat with the second cooling member when the first coolingmember reaches a temperature threshold. The system may further comprisea temperature sensor that senses the temperature of the first coolingmember. The first cooling member may exchange heat with the secondcooling member after formation of a prescribed number of layers ofhardened material as part of the 3D object. The prescribed number oflayers may be one layer. The system may further comprise a third coolingmember comprising a heat conductive material. The third cooling membercan be separated from the material bed by a gap comprising a gas. Thethird cooling member may be mobile during formation of thethird-dimensional object. The third cooling member may be mobile duringoperation (i). The third cooling member may be disposed in theenclosure. The controller may be operatively coupled to the thirdcooling member. The controller may further be programmed to direct thethird cooling member to exchange heat with the second cooling member(e.g., during formation of the 3D object).

In another aspect, an apparatus for generating a 3D object comprises atleast one controller that is programmed to (a) direct an energy beam totransform at least a portion of a material bed to form the 3D object,wherein the material bed is disposed in an enclosure; (b) direct a firstcooling member to cool the material bed while moving during thegenerating of the 3D object (e.g., during operation (a)), wherein thefirst cooling member comprises a heat conductive material, wherein thefirst cooling member is separated from an exposed surface of thematerial bed by a gap; and (c) direct the first cooling member toexchange heat with a second cooling member during formation of the 3Dobject, wherein the second cooling member comprises an opening, whereinthe second cooling member is disposed outside of the enclosure or at awall of the enclosure, wherein the controller is operatively coupled tothe energy beam, the first cooling member, and the second coolingmember. A at least one of operations (a) to (c) may be controlled by thesame controller. At least one controller may comprise a multiplicity ofcontrollers. At least one of (a) to (c) may be controlled by differentcontrollers.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed disposed in an enclosure; (b) an energy source generatingan energy beam that transforms at least a portion of the material bed toform the 3D object, wherein the energy source is disposed adjacent tothe enclosure; (c) a first cooling member comprising a heat conductivematerial, which first cooling member is separated from the material bedby a gap comprising a gas, which first cooling member is mobile, whereinthe first cooling member is disposed in the enclosure; and (d) a secondcooling member comprising an opening, which second cooling member isstationary, wherein the second cooling member is disposed at a wall ofthe enclosure or outside of and adjacent to the enclosure.

The second cooling member can be actively cooling the first coolingmember that is passive. The first cooling member can be mobile duringformation of the 3D object. The second cooling member may cool the firstcooling member during formation of the 3D object.

In another aspect, a computer software product for 3D printing of atleast one 3D object, comprises a non-transitory computer-readable mediumin which program instructions are stored, which instructions, when readby at least one computer, cause the at last one computer to performoperations comprising: (a) direct an energy beam to transform at least aportion of a material bed to the 3D object, wherein the material bed isdisposed in an enclosure; (b) direct a first cooling member to cool thematerial bed during formation of the 3D object, wherein the firstcooling member is mobile during the formation, wherein the first coolingmember is disposed in the enclosure, wherein the first cooling member isseparated from an exposed surface of the material bed by a gapcomprising a gas, wherein the first cooling member comprises a heatconductive material; and (c) direct the first cooling member tophysically contact a second cooling member to cool the first coolingmember, wherein the second cooling member is disposed (i) at anenclosure wall or (ii) outside of the enclosure, wherein the secondcooling member is stationary, wherein the second cooling membercomprises an opening, wherein the first cooling member, the secondcooing member, the energy beam and the at least one computer areoperatively coupled.

The physically contact can comprise a direct physical contact betweenthe first and second cooling member. The physically contact may comprisean indirect physical contact between the first and second cooling memberthough one or more materials (e.g., mediators). The one or morematerials can comprise a solid material. The at least one computer canbe a multiplicity of computers. At least two of operations (a) to (c)may be performed by different computers. The multiplicity of computersmay be operatively coupled. At least two of operations (a) to (c) can beperformed by the same computer.

In another aspect, a method for forming a 3D object comprises: (a)providing a first structure having a bottom surface with a firstcurvature that is negative, which structure comprises a hardenedmaterial and is disposed in a material bed adjacent to a platform; and(b) transforming at least a portion of the material bed into atransformed material that is coupled to the top of the first structureto form a second structure, which transformed material hardens into ahardened material as part of the 3D object, wherein a bottom surface ofthe second structure has a second curvature that is greater than thefirst curvature, wherein the first curvature is negative when a volumebound from the bottom surface to the platform is a convex object, whichbottom surface is disposed above the platform, wherein bottom faces theplatform, wherein top faces away from the platform.

Coupled may be attached. The curvature of the bottom surface of thesecond structure may be at most about 0.02 millimeter⁽⁻¹⁾. The materialbed can be a powder bed. During formation the 3D object may be suspended(e.g., float) anchorless in the material bed. The 3D may be formedwithout one or more auxiliary support features. The method may furthercomprise prior to operation (a), transforming at least a portion of thematerial bed into a transformed material, which transformed materialhardens into a hardened material as part of the negatively warpedobject. The first structure may be generated by 3D printing. The 3Dprinting may be additive manufacturing. The additive manufacturing maycomprise selective laser sintering or selective laser melting.

In another aspect, a system for forming a 3D object, comprises: (a) amaterial bed disposed adjacent to a platform comprising a firststructure having a bottom surface with a first curvature that isnegative, which structure comprises a hardened material; (b) an energysource generating an energy beam that transforms at least a portion ofthe material bed into a transformed material; and (c) a controlleroperatively coupled to the material bed and to the energy beam and isprogrammed to direct the energy beam to transform at least a portion ofthe material bed into a transformed material that couples to the top ofthe first structure to form a second structure, which transformedmaterial hardens into a hardened material as part of the 3D object,wherein a bottom surface of the second structure has a second curvaturethat is greater than the first curvature, wherein the first curvature isnegative when a volume bound from the bottom surface to the platform isa convex object, which bottom surface is disposed above the platform,wherein bottom faces the platform, wherein top faces away from theplatform. The curvature of the bottom surface of the second structuremay be at most about 0.02 (1/millimeter).

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is operatively coupled to an energy beam and isprogrammed to direct the energy beam to transform at least a portion ofa material bed into a transformed material that couples to a top surfaceof a first structure to form a second structure, which first structurehas a bottom surface with a first curvature that is negative and isdisposed in the material bed, which transformed material hardens into ahardened material as part of the 3D object, wherein a bottom surface ofthe second structure has a second curvature that is greater than thefirst curvature, wherein the first curvature is negative when a volumebound from the bottom surface to the platform is a convex object, whichbottom surface is disposed above the platform, wherein bottom faces theplatform, wherein top faces away from the platform.

The controller may be operatively coupled to a leveling member and isprogrammed to direct the leveling member to level the exposed surface ofthe material bed. The controller may be operatively coupled to amaterial removal member and is programmed to direct the material removalmember to remove material from the material bed. The removal of thematerial from the material bed may result in a substantially planarexposed surface of the material bed. The removal may exclude contactingthe exposed surface of the material bed.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed comprising a first structure of hardened material; and (b)an energy source generating an energy beam, which energy source isdisposed adjacent to the material bed, which energy beam transforms atleast a portion of the material bed into a transformed material thatcouples to a top surface of a first structure to form a secondstructure, which first structure has a bottom surface with a firstcurvature that is negative and is disposed in the material bed, whichtransformed material hardens into a hardened material as part of the 3Dobject, wherein a bottom surface of the second structure has a secondcurvature that is greater than the first curvature, wherein the firstcurvature is negative when a volume bound from the bottom surface to theplatform is a convex object, which bottom surface is disposed above theplatform, wherein bottom faces the platform, wherein top faces away fromthe platform.

In another aspect, a method for forming a 3D object comprises: (a)forming a first layer of hardened material in a material bed thatcomprises an pre-transformed material, which material bed is disposedadjacent to a platform; (b) disposing an upper layer of pre-transformedmaterial above the first layer of hardened material; (c) generating alayer of hardened material from at least a portion of the upper layer ofpre-transformed material, wherein the first layer of hardened materialis separated from the second layer of hardened material by a gap,wherein the gap comprises a material that is less dense than either thefirst layer of hardened material and the second layer of hardenedmaterial, wherein above is relative to a direction away from theplatform.

The method may further comprise after operation (a) and before operation(b) disposing a leveled layer of pre-transformed material on the firstlayer of hardened material. The pre-transformed material may be a powdermaterial. The gap may comprise the powder material. The powder materialmay be at least partially sintered. The gap may comprise portions ofhardened material and portions that include powder material or sinteredpowder material. The portions may be distributed across the gap. Theportions may be concentrated within the gap. The method may furthercomprise transforming the material within the gap to form a transformedmaterial that subsequently hardens into a hardened material as a portionof the 3D object. The curvature of the first layer of hardened materialand of the second layer of hardened material may be at most about 0.02millimeter⁽⁻¹⁾ (i.e., 1/millimeter).

In another aspect, a system for forming a 3D object comprises: (a) amaterial dispenser that dispenses pre-transformed material to form amaterial bed comprising a first layer of hardened material andpre-transformed material, which material bed is disposed adjacent to aplatform; (b) an energy source generating an energy beam that transformsat least a portion of the material bed into a transformed material; and(c) a controller operatively connected to the material dispenser and tothe energy beam and is programmed to: (i) direct the material dispenserto dispose an upper layer of pre-transformed material above the firstlayer of hardened material; (ii) direct the energy beam to generate alayer of hardened material from at least a portion of the upper layer ofpre-transformed material, wherein the first layer of hardened materialis separated from the second layer of hardened material by a gap,wherein the gap comprises a material that is less dense than either thefirst layer of hardened material and the second layer of hardenedmaterial, wherein above is relative to a direction away from theplatform.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to (i) direct a material dispenser todispose an upper layer of pre-transformed material above a first layerof hardened material in a material bed comprising pre-transformedmaterial, which material bed is disposed adjacent to a platform; and(ii) direct an energy beam to generate a layer of hardened material fromat least a portion of the upper layer of pre-transformed material,wherein the first layer of hardened material is separated from thesecond layer of hardened material by a gap, wherein the gap comprises amaterial that is less dense than either the first layer of hardenedmaterial and the second layer of hardened material, and wherein thecontroller is operatively coupled to the material dispenser and to theenergy beam, wherein above is relative to a direction away from theplatform.

The controller may be operatively coupled to a leveling member and isprogrammed to direct the leveling member to level the exposed surface ofthe material bed. The controller may be operatively coupled to amaterial removal member and is programmed to direct the material removalmember to remove material from the material bed. The removal of thematerial from the material bed can result in a substantially planarexposed surface of the material bed. The removal may exclude contactingthe exposed surface of the material bed.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed comprising an upper layer of pre-transformed material abovea first layer of hardened material that is embedded in pre-transformedmaterial within the material bed, which material bed is disposedadjacent to a platform; and (b) an energy source generating an energybeam to generate a layer of hardened material from at least a portion ofthe upper layer of pre-transformed material, wherein the first layer ofhardened material is separated from the second layer of hardenedmaterial by a gap, wherein the gap comprises a material that is lessdense than either the first layer of hardened material and the secondlayer of hardened material, and wherein the energy source is disposedadjacent to the material bed, wherein above is relative to a directionaway from the platform.

In another aspect, a method for forming a 3D object comprises: (a)forming a hardened material in a material bed comprising pre-transformedmaterial, wherein the material of the hardened material and material bedsubstantially excludes a resin and a polymer that comprises repeatingmolecular units, which polymer and resin are organic; (b) disposing alayer of pre-transformed material on the hardened material; (c) meltinga portion of the layer to form a molten portion; (d) hardening theexposed surface of the molten portion while the interior of the moltenportion remains molten; and (e) hardening the molten portion to form atleast a portion of the 3D object.

The material of the hardened material and of the material bed can beselected from the group consisting of elemental metal, metal alloy,ceramics, and an allotrope of elemental carbon. The material of thehardened material and material bed can be selected from the groupconsisting of elemental metal and metal alloy. The pre-transformedmaterial can be a powder material. The method can further comprise inoperation (e), cooling the molten portion for the hardening. Thehardened material may be a solidified material. Hardens may besolidifies. The method may reduce a curvature of at least one surface ofthe 3D object. The method may reduce the curvature such that the atleast one surface of the 3D object comprises a positive curvature,negative curvature, or substantially zero curvature.

In another aspect, a system for forming a 3D object comprises: (a) amaterial dispenser that dispenses pre-transformed material to form amaterial bed that comprises a hardened material and pre-transformedmaterial, wherein the material of the pre-transformed material andhardened material substantially excludes a resin and a polymer thatcomprises repeating molecular units, which polymer and resin areorganic; (b) an energy source generating an energy beam that transformsat least a portion of the material bed into a transformed material; (c)a cooling member; and (d) a controller operatively connected to thematerial dispenser, energy beam, and cooling member and is programmedto: (i) direct the material dispenser to dispose a layer ofpre-transformed material on the hardened material; (ii) direct theenergy beam to melt a portion of the layer to form a molten portion;(iii) direct the cooling member to harden the exposed surface of themolten portion while keeping the interior of the molten portion molten;and (iv) direct the cooling member to harden the molten portion to format least a portion of the 3D object.

The material may comprise an elemental metal, metal alloy, ceramics, oran allotrope of elemental carbon.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to (a) direct a material dispenser todispose a layer of pre-transformed material on a hardened materialdisposed in a material bed, wherein the material of the pre-transformedmaterial and hardened material substantially excludes a resin and apolymer that comprises repeating molecular units, which polymer andresin are organic, which controller is operatively coupled to thematerial dispenser; (b) direct an energy beam to melt a portion of thelayer of pre-transformed material to form a molten portion, whichcontroller is operatively coupled to the energy beam; (c) direct acooling member to harden the exposed surface of the molten portion whilekeeping the interior of the molten portion molten, which cooling memberis operatively coupled to the controller; and (d) direct the coolingmember to harden the molten portion to form at least a portion of the 3Dobject. The material may comprise an elemental metal, metal alloy,ceramics, or an allotrope of elemental carbon.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed comprising a layer of pre-transformed material on ahardened material, wherein the material of the pre-transformed materialand hardened material substantially excludes a resin and a polymer thatcomprises repeating molecular units, which polymer and resin areorganic; (b) an energy source generating an energy beam to melt aportion of the layer of pre-transformed material to form a moltenportion, which energy source is disposed adjacent to the material bed;(c) a cooling member that (i) hardens the exposed surface of the moltenportion while keeping the interior of the molten portion molten, and(ii) hardens the molten portion to form at least a portion of the 3Dobject, which cooling member is disposed adjacent to the material bed.The material bed can be disposed adjacent to a platform and wherein thecooling member is disposed above the material bed. Above can be in thedirection away from the platform.

In another aspect, a method for forming a 3D object comprises: (a)forming a first hardened material in a material bed comprisingpre-transformed material, wherein the material of the first hardenedmaterial and the pre-transformed material substantially excludes a resinand a polymer that comprises repeating molecular units, which polymerand resin are organic; (b) disposing a layer of pre-transformed materialon the first hardened material; (c) melting a portion of the layer and aportion of the first hardened material to form a molten portion and aremainder of the first hardened material; and (d) hardening the moltenportion to form a second hardened material and plastically deforming aregion comprising (i) a portion of the second hardened material, and(ii) a portion of the remainder of the first hardened material that isbordering the second hardened material, wherein the region comprises anexposed surface and an interior, which exposed surface ceases toplastically deform before the interior ceases to plastically deform,wherein the hardening forms at least a portion of the 3D object.

The material of the first hardened material and the pre-transformedmaterial can be selected from the group consisting of elemental metal,metal alloy, ceramics, and an allotrope of elemental carbon. Thematerial of the first hardened material and the pre-transformed materialcan be selected from the group consisting of elemental metal and metalalloy. Melting can be melting together a portion of the layer and aportion of the first hardened material to form a molten portion, andwherein the hardening is solidifying. The method may control (e.g.,regulate) the curvature of at least one surface of the 3D object. Duringformation, the 3D object may be suspended (e.g., float) anchorless inthe material bed. The method may reduce the curvature of at least onesurface of the 3D object. The method may result in the formation apositive curvature, negative curvature, or substantially zero curvaturein the at least one surface of the 3D object. The method may form apositive curvature, negative curvature, or substantially zero curvaturein the at least one surface of the 3D object. The hardening operationmay occur before the deforming operation. The method may furthercomprise after the hardening operation and before a completion of theplastically deforming operation, heating the second hardened material.The method may further comprise after the hardening operation and beforea completion of the plastically deforming operation, cooling the secondhardened material. The method may further comprise after the hardeningoperation and before a completion of the plastically deformingoperation, heating the second hardened material followed by cooling thesecond hardened material. The cooling operation may comprise coolingfrom above the exposed surface, wherein above is the direction opposingthe platform.

In another aspect, a system for forming 3D object comprises: (a) amaterial dispenser that dispenses pre-transformed material to form amaterial bed, which material bed comprises a first hardened material andan pre-transformed material, wherein the material of the first hardenedmaterial and the pre-transformed material substantially excludes a resinand a polymer that comprises repeating molecular units, which polymerand resin are organic; (b) an energy source generating an energy beamthat melts at least a portion of the pre-transformed material; (c) acooling member; and (d) a controller operatively coupled to the materialdispenser, the energy beam, and the cooling member, and is programmedto: (i) direct the material dispenser to dispose a layer ofpre-transformed material on the first hardened material; (ii) direct theenergy beam to melt a portion of the layer of pre-transformed materialand a portion of the first hardened material to form a molten portionand a remainder of the first hardened material; and (iii) direct thecooling member to harden the molten portion to form a second hardenedmaterial and plastically deform a region comprising (1) a portion of thesecond hardened material, and (2) a portion of the remainder of thefirst hardened material that is bordering the second hardened material,wherein the region comprises an exposed surface and an interior, whichexposed surface ceases to plastically deform before the interior ceasesto plastically deform, wherein the hardening forms at least a portion ofthe 3D object. The cooling member may be a heat-sink.

In another aspect, an apparatus for forming 3D object comprising acontroller that is programmed to: (a) direct a material dispenser todispose a layer of pre-transformed material on a first hardened materialthat is disposed in the material bed, wherein the material of the firsthardened material and the pre-transformed material substantiallyexcludes a resin and a polymer that comprises repeating molecular units,which polymer and resin are organic, wherein the controller isoperatively coupled to the material dispenser; (b) direct an energy beamto melt a portion of the layer of pre-transformed material and a portionof the first hardened material to form a molten portion and a remainderof the first hardened material, wherein the controller is operativelycoupled to the energy beam; and (c) direct a cooling member to hardenthe molten portion to form a second hardened material and plasticallydeform a region comprising (i) a portion of the second hardenedmaterial, and (ii) a portion of the remainder of the first hardenedmaterial that is bordering the second hardened material, wherein theregion comprises an exposed surface and an interior, which exposedsurface ceases to plastically deform before the interior ceases toplastically deform, wherein the hardening forms at least a portion ofthe 3D object, wherein the controller is operatively coupled to thecooling member.

The controller can be operatively coupled to a leveling member and canbe programmed to direct the leveling member to level the exposed surfaceof the material bed. The controller can be operatively coupled to amaterial removal member and can be programmed to direct the materialremoval member to remove material from the material bed. The removal ofthe material from the material bed may result in a substantially planarexposed surface of the material bed. The removal may exclude contactingthe exposed surface of the material bed.

In another aspect, an apparatus for forming 3D object comprises: (a) amaterial bed comprising a layer of pre-transformed material on a firsthardened material, wherein the material of the first hardened materialand the pre-transformed material substantially excludes a resin and apolymer that comprises repeating molecular units, which polymer andresin are organic; (b) an energy source generating an energy beam tomelt a portion of the layer of pre-transformed material and a portion ofthe first hardened material to form a molten portion and a remainder ofthe first hardened material, wherein the energy beam is disposedadjacent to the material bed; and (c) a cooling member that hardens themolten portion to form a second hardened material and plastically deforma region comprising (i) a portion of the second hardened material, and(ii) a portion of the remainder of the first hardened material that isbordering the second hardened material, wherein the region comprises anexposed surface and an interior, which exposed surface ceases toplastically deform before the interior ceases to plastically deform,wherein the hardening forms at least a portion of the 3D object, whereinthe cooling member is disposed adjacent to the material bed. Thematerial bed can be disposed adjacent to a platform. The cooling membercan be disposed above the material bed. Above can be in the directionaway from the platform in a direction opposite to the gravitationalfield.

In another aspect, a 3D object formed by a 3D printing processcomprises: one or more layer portions comprising successive solidifiedmelt pools of a material, wherein the 3D object comprises a surface, aninterior, and a grain structure, wherein the grain structure at aposition closer to or at the surface is indicative of a greatersolidification rate than the grain structure in the interior, whereinthe material substantially excludes a resin and a polymer that comprisesrepeating molecular units, which polymer and resin are organic.

The material can be selected from the group consisting of elementalmetal, metal alloy, ceramics, and an allotrope of elemental carbon. Thematerial can be selected from the group consisting of elemental metaland metal alloy. The grain structure can be smaller at closer to thesurface, as compared to the size of the grain structure in the interior.Solidification may comprise crystallization. The material can comprisean elemental metal or metal alloy. The grain structure can be ametallurgical structure.

In another aspect, a system for forming a 3D object comprises: (a) amaterial bed comprising pre-transformed material, wherein the materialbed is formed of a material that substantially excludes a resin and apolymer that comprises repeating molecular units, which polymer andresin are organic; (b) an energy source generating an energy beam thattransforms at least a portion of the material bed; and (c) a controllerthat is operatively coupled to the material bed and to the energy beam,and is programmed to: direct the energy beam to transform at least aportion of a material bed and form the 3D object comprising one or morelayer portions having successive solidified melt pools of a material,wherein the 3D object comprises a surface, an interior, and a grainstructure, wherein the grain structure at a position closer to or at thesurface is indicative of a greater solidification rate than the grainstructure in the interior.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to: direct an energy beam to transform atleast a portion of a material bed and form a 3D object comprising one ormore layer portions having successive solidified melt pools of amaterial, wherein the 3D object comprises a surface, an interior, and agrain structure, wherein the grain structure at a position closer to orat the surface is indicative of a greater solidification rate than thegrain structure in the interior, wherein the controller is operativelycoupled to the material bed and to the energy beam, wherein the materialbed is formed of a material that substantially excludes a resin and apolymer that comprises repeating molecular units, which polymer andresin are organic.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed comprising pre-transformed material; and (b) an energysource generating an energy beam to transform at least a portion of thematerial bed and forms a 3D object comprising one or more layer portionshaving successive solidified melt pools of a material, wherein the 3Dobject comprises a surface, an interior, and a grain structure, whereinthe grain structure at a position closer to or at the surface isindicative of a greater solidification rate than the grain structure inthe interior, wherein the controller is operatively coupled to thematerial bed and to the energy beam, and wherein the energy beam isdisposed adjacent to the material bed, wherein the pre-transformedmaterial substantially excludes a resin and a polymer that comprisesrepeating molecular units, which polymer and resin are organic.

In another aspect, a 3D object formed by a 3D printing processcomprises: one or more layer portions comprising successive solidifiedmelt pools of a material, wherein the 3D object comprises a surface, aninterior, and dendrites, wherein the dendrites at a position closer toor at the surface are indicative of a greater solidification rate thanthe dendrites in the interior, wherein the material substantiallyexcludes a resin and a polymer that comprises repeating molecular units,which polymer and resin are organic.

The material can be selected from the group consisting of elementalmetal, metal alloy, ceramics, and an allotrope of elemental carbon. Thematerial can be selected from the group consisting of elemental metaland metal alloy. The spacing between the dendrites can be smaller at aposition closer to or at the surface, as compared to the spacing of thedendrites in the interior. The overall size of the dendrites can besmaller at a position closer to or at the surface, as compared to theoverall size of the dendrites in the interior. The material can comprisean elemental metal, metal alloy, ceramic, or an allotrope of elementalcarbon. The material can comprise an elemental metal, metal alloy,ceramic, or an allotrope of elemental carbon. The 3D object can bedevoid of an auxiliary support feature or auxiliary support feature markthat is indicative of a presence or removal of the auxiliary supportfeature.

In another aspect, a system for forming a 3D object comprises: (a) amaterial bed comprising pre-transformed material, wherein the materialbed is formed of a material that substantially excludes a resin and apolymer that comprises repeating molecular units, which polymer andresin are organic; (b) an energy source generating an energy beam thattransforms at least a portion of the material bed; and (c) a controllerthat is operatively coupled to the material bed and to the energy beam,and is programmed to: direct the energy beam to transform at least aportion of a material bed and form the 3D object comprising one or morelayer portions having successive solidified melt pools of a material,wherein the 3D object comprises a surface, an interior, and dendrites,wherein the dendrites at a position closer to or at the surface areindicative of a greater solidification rate than the dendrites in theinterior.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to: direct an energy beam to transform atleast a portion of a material bed and form a 3D object comprising one ormore layer portions having successive solidified melt pools of amaterial, wherein the 3D object comprises a surface, an interior, anddendrites, wherein the dendrites at a position closer to or at thesurface are indicative of a greater solidification rate than thedendrites in the interior, wherein the controller is operatively coupledto the material bed and to the energy beam, wherein the material bed isformed of a material that substantially excludes a resin and a polymerthat comprises repeating molecular units, which polymer and resin areorganic.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed; and (b) an energy beam to transform at least a portion ofthe material bed and form a 3D object comprising one or more layerportions having successive solidified melt pools of a material, whereinthe 3D object comprises a surface, an interior, and dendrites, whereinthe dendrites at a position closer to or at the surface are indicativeof a greater solidification rate than the dendrites in the interior,wherein the controller is operatively coupled to the material bed and tothe energy beam, and wherein the energy beam is disposed adjacent to thematerial bed, wherein the pre-transformed material substantiallyexcludes a resin and a polymer that comprises repeating molecular units,which polymer and resin are organic.

In another aspect, a method for forming a 3D object comprises: (a)generating a material bed comprising a first hardened material, whichmaterial bed is disposed adjacent to a platform in an enclosure, whichfirst hardened material comprises a bottom surface facing towards theplatform; (b) heating a portion of the first hardened material to form aheated portion; (c) melting a portion of the top of the heated portionto form a molten portion; and (d) hardening the molten portion to form asecond hardened material that comprises a bottom surface facing towardsthe platform, wherein the bottom surface of the first hardened materialhas a first curvature that is of a higher a second curvature of thebottom surface of the second hardened material, wherein the bottomsurface has a negative curvature when a volume bound from the bottomsurface to the platform is a convex object, which bottom surface isdisposed above the platform, wherein the first hardened materialsubstantially excludes a resin and a polymer that comprises repeatingmolecular units, which polymer and resin are organic.

An exposed surface of the molten portion can be contained within and anexposed surface of the heated portion. An exposed surface of the moltenportion can be smaller than an exposed surface of the heated portion.The heated portion may not comprise the rim of the layer of hardenedmaterial. The method may further comprise removing a portion of themolten portion. The removal of a portion of the molten portion maycomprises ablating. The method may further comprise removing a portionof the heated portion. The ablating operation may comprise using anenergy beam. The energy beam may comprise electromagnetic or chargedparticle radiation. The energy beam may comprise a laser beam. Thepre-transformed material may be a powder material. The material bed maybe a powder bed. The layer of hardened material may not be anchored tothe platform. The layer of hardened material may not be anchored to theenclosure. The layer of hardened material may float anchorless in thematerial bed.

In another aspect, a system for forming a 3D object comprises: (a) amaterial bed disposed adjacent to a platform, which material bedcomprising a first hardened material that comprises a bottom surfacefacing towards the platform; (b) a first energy source generating afirst heat energy that heats at least a portion of the first hardenedmaterial; (c) a second energy source that generates a second energy beamthat melts a portion of the heated portion to form a molten portion; (d)a cooling member; and (e) a controller operatively coupled to thematerial bed, the first heating energy, the second energy beam, and thecooling member, and is programmed to: (i) direct the first heat energyto heat at least a portion of the first hardened material to form aheated portion; (ii) direct the second energy beam to melt at least aportion of the heated portion to form a molten portion; and (iii) directthe cooling member to cool the molten portion to form a second hardenedmaterial that comprises a bottom surface facing towards the platform,wherein the bottom surface of the first hardened material has a firstcurvature that is higher than a second curvature of the bottom surfaceof the second hardened material, wherein the bottom surface has anegative curvature when a volume bound from the bottom surface to theplatform is a convex object, which bottom surface is disposed above theplatform, wherein the first hardened material substantially excludes aresin and a polymer that comprises repeating molecular units, whichpolymer and resin are organic.

The first energy source and the second energy source may be the sameenergy source. The first energy source and the second energy source maybe different energy sources. The first heat energy may not transform thehardened material. The first heat energy can be a first energy beam. Thefirst energy beam and the second energy beam can be the same energybeam. The first energy beam and the second energy beam can be differentenergy beams. The first heat energy can comprise a radiative heatsource.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to: (a) direct a material dispenser todispense pre-transformed material to form a material bed disposedadjacent to a platform, which material bed comprises a first hardenedmaterial that comprises a bottom surface facing towards the platform;(b) directing a first heat energy to heat at least a portion of thefirst hardened material; (c) direct a second energy beam to melt aportion of the heated portion to form a molten portion; (d) direct thecooling member to cool the molten portion to form a second hardenedmaterial that comprises a bottom surface facing towards the platform,wherein the bottom surface of the first hardened material has a firstcurvature that is higher than a second curvature of the bottom surfaceof the second hardened material, wherein the bottom surface has anegative curvature when a volume bound from the bottom surface to theplatform is a convex object, which bottom surface is disposed above theplatform, wherein the first hardened material substantially excludes aresin and a polymer that comprises repeating molecular units, whichpolymer and resin are organic, wherein the controller is operativelycoupled to the material dispenser, the first heat energy, the secondenergy beam, and the cooling member.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed disposed adjacent to a platform, which material bedcomprises a first hardened material that comprises a first bottomsurface facing towards the platform; (b) a first energy sourcegenerating a first heat energy that heats at least a portion of thefirst hardened material, which first energy source is disposed adjacentto the material bed; (c) a second energy source generating a secondenergy beam that melts a portion of the heated portion to form a moltenportion, which second energy source is disposed adjacent to the materialbed; and (d) a cooling member that cools the molten portion to form asecond hardened material that comprises a second bottom surface facingtowards the platform, which cooling member is disposed adjacent to thematerial bed, wherein the first bottom surface has a first curvaturethat is higher than a second curvature of the second bottom surface,wherein the first bottom surface or second bottom surface has a negativecurvature when a volume bound from the bottom surface to the platform isa convex object, which first bottom surface or second bottom surface isdisposed above the platform, wherein the first hardened materialsubstantially excludes a resin and a polymer that comprises repeatingmolecular units, which polymer and resin are organic.

The cooling member may be disposed above the exposed surface of thematerial bed. The cooling member may be movable to and away from aposition above the molten portion.

In another aspect, a method for forming a 3D object comprises: (a)generating at least a portion of a 3D object from a material beddisposed on a platform within an enclosure; (b) cooling the material bedusing a first cooling member disposed within the enclosure and above anexposed surface of the material bed; (c) moving the first coolingmember; and (d) cooling the first cooling member using a second coolingmember that is disposed outside of the enclosure, wherein above refersto a direction away from the platform.

The first cooling member can be disposed along the path of an energybeam that is used in the generating. The first cooling member can bedisposed in an isolated atmosphere. The first cooling member and thematerial bed can be disposed in an isolated atmosphere. The secondcooling member can be disposed in an ambient atmosphere. The cooling inoperation (c) comprises contacting the first cooling member with thesecond cooling member. The contacting can be indirect contacting througha surface of the enclosure. The contacting can be direct contactingbetween the first cooling member and the second cooling member. Thefirst cooling member can be passive. The second cooling member can beactively cooled. The second cooling member can comprise a heatexchanger. The material bed can be a powder bed. The powder can compriseelemental metal, metal alloy, ceramics, or an allotrope of elementalcarbon. The first cooling member can be translatable. The second coolingmember can be stationary. The method may further comprise translatingthe first cooling member to a position adjacent to the second coolingmember.

The generating can comprise transforming the material within thematerial bed. The transforming can comprise melting or sintering. Themethod may further comprise attracting the first cooling member to thesecond cooling member. The attracting can comprise generating a forcethat attracts the first cooling member to the second cooling member. Theforce can comprise magnetic, hydraulic, or electric force. The firstcooling member can be disposed adjacent to an exposed surface of thematerial bed. Adjacent can be above. Cooling of the material bed usingthe first cooling member can comprise removing at least about 30 percentof the heat in the material bed from an exposed surface of the materialbed.

In another aspect, a system for forming a 3D object comprises: (a) anenergy source generating an energy beam that transforms at least aportion of a material bed into a transformed material, which materialbed comprises pre-transformed material and is disposed in an enclosure;(b) a first cooling member that (i) cools the material bed (ii) istranslatable, and (iii) is disposed within the enclosure; (c) a secondcooling member that cools the first cooling member, which second coolingmember is not disposed in the enclosure; and (d) a controller that isoperatively coupled to the energy source, the first cooling member, andthe second cooling member, and is programmed to: (i) direct the energybeam to transform at least a portion of the material bed into atransformed material; (ii) direct the first cooling member to cool thematerial bed; and (iii) direct the second cooling member to cool thefirst cooling member.

The second cooling member can be disposed outside of the enclosure. Thesecond cooling member can be part of a coating of the enclosure. Thecoating can be a wall or a rim. The first cooling member can be disposedadjacent to the material bed, wherein adjacent is above, wherein aboveis in the direction opposite to the platform.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to: (a) direct an energy beam to transformat least a portion of a material bed into a transformed material; (b)direct a first cooling member that is translatable to cool the materialbed; and (c) direct a second cooling member to cool the first coolingmember, wherein the controller is operatively coupled to the energybeam, the first cooling member, and the second cooling member.

In another aspect, an apparatus for forming a 3D object comprises: (a) amaterial bed disposed in an enclosure; (b) an energy source generatingan energy beam to transform at least a portion of a material bed into atransformed material; (c) a first cooling member that (i) cools thematerial bed, (ii) is movable, and (iii) is disposed in the enclosure;and (d) a second cooling member that cools the first cooling member andis not disposed in the enclosure.

In another aspect, a method for forming a 3D object comprises: using anenergy beam to transform at least a portion of a material bed to form atleast a portion of the 3D object; measuring one or more temperatures ofone or more points on the at least a portion of the 3D object; andcontrolling the energy beam with at least one processor based on themeasured temperatures, wherein the at least one processor comprises atleast 3 Tera floating point operations per second, according to abenchmark.

Controlling the energy beam with a processor can be based (e.g., furtherbased) on a geometry of the at least a portion of the 3D object. Thebenchmark can be a mathematical, graphical, or encryption benchmark. Theprocessor can comprise parallel processing. The processor can compriseat least 8 billion transistors. The area of the at least one processormay be at most about 600 mm². The processor can comprise at least 1000cores. The processor may have a memory bandwidth of at least 100 Gigabytes per second. The processor may have a memory clock speed of atleast 5 Giga bits per second. Controlling can be based on (e.g., dependon) a control mechanism that excludes feedback from the structure of atleast a portion of the generated 3D object. Controlling can be based ona control mechanism comprising taking into account a generic geometricsection that is similar to a portion of the 3D object.

In another aspect, a system for forming a 3D object comprises: (a) anenergy beam that transforms at least a portion of a material bed; (b)one or more sensors measuring temperatures of one or more points on theat least a portion of the 3D object; and (c) a controller comprising atleast one processor, which controller is operative coupled to the energybeam and to the one or more sensors and is programmed to: (i) direct theenergy beam to transform the at least a portion of the material bed toform the 3D object; (ii) direct the one or more sensors measure one ormore temperatures of one or more points on at least a portion of the 3Dobject; and (iii) control the energy beam with the at least oneprocessor based on the measured one or more temperatures, wherein the atleast one processor comprises at least 3 Tera floating point operationsper second, according to a benchmark.

In another aspect, an apparatus for forming a 3D object comprises: acontroller that is programmed to (a) direct an energy beam to transformthe at least a portion of the material bed to form the 3D object; (b)direct one or more sensors to measure one or more temperatures of one ormore points on the at least a portion of the 3D object; and (c) controlthe energy beam with at least one processor based on the measured one ormore temperatures, wherein the at least one processor comprises at least3 Tera floating point operations per second, according to a benchmark.

In another aspect, an apparatus for forming a 3D object comprises: (a)an energy beam that transforms at least a portion of a material bed toform at least a portion of the 3D object; (b) one or more sensors thatmeasure temperatures of one or more points on the at least a portion ofthe 3D object, which one or more sensors are disposed adjacent to thematerial bed; and (c) a controller comprising at least one processorthat controls the energy beam based on the measured one or moretemperatures, wherein the at least one processor comprises at least 3Tera floating point operations per second, according to a benchmark,which controller is operatively coupled to the energy beam and to theone or more sensors. The control (e.g., regulate and/or direct) of theenergy beam can be further based on (e.g., depend on) a geometry of theat least a portion of the 3D object. The control of the energy beam maybe based on (e.g., further based on) a geometry of the at least aportion of the 3D object. A controller that is programmed to direct anenergy beam along the path can comprise the at least one processor. Theformation of the 3D object may comprise hardening the transformedmaterial to form the 3D object.

Another aspect of the present disclosure provides a non-transitorycomputer-readable medium comprising machine-executable code that, uponexecution by one or more computer processors, implements any of themethods above or elsewhere herein.

Another aspect of the present disclosure provides a computer systemcomprising one or more computer processors and a non-transitorycomputer-readable medium coupled thereto. The non-transitorycomputer-readable medium comprises machine-executable code that, uponexecution by the one or more computer processors, implements any of themethods above or elsewhere herein.

Additional aspects and advantages of the present disclosure will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein only illustrative embodiments of thepresent disclosure are shown and described. As will be realized, thepresent disclosure is capable of other and different embodiments, andits several details are capable of modifications in various obviousrespects, all without departing from the disclosure. Accordingly, thedrawings and description are to be regarded as illustrative in nature,and not as restrictive.

Incorporation by Reference

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings or figures (also “FIG.” and “FIGs.” herein), ofwhich:

FIGS. 1A-1C illustrate schematic vertical cross sections ofthree-dimensional (3D) objects.

FIG. 2 illustrates a schematic vertical cross section of layers of 3Dobjects;

FIGS. 3A-3F illustrate schematic vertical cross sections of 3D objects;

FIGS. 4A-4F illustrate schematic vertical cross sections of 3D objects;

FIGS. 5A-5B illustrate schematic side views of systems and apparatusesfor forming one or more 3D objects;

FIGS. 6A-6C illustrate schematic vertical cross sections of 3D objects;

FIG. 7 illustrates a schematic side view of a system and apparatuses forforming one or more 3D objects.

FIGS. 8A-8C illustrates various 3D objects and schemes thereof;

FIG. 9 schematically illustrates a coordinate system;

FIG. 10 shows a horizontal view of a 3D object;

FIGS. 11A-11F illustrate schematic vertical cross sections of 3Dobjects;

FIG. 12 schematically illustrates a flow chart for the formation of oneor more 3D objects;

FIG. 13 schematically illustrates a controller (e.g., control system)used in the formation of one or more 3D objects;

FIG. 14 schematically illustrates a computer control system that isprogrammed or otherwise configured to facilitate the formation of one ormore 3D objects;

FIGS. 15A-15C schematically illustrate a horizontal view of 3D objects;

FIG. 16 schematically illustrates various paths;

FIG. 17 shows a vertical cross section of a 3D object; and

FIGS. 18A-18B illustrate schematic side views of systems and apparatusesfor forming one or more 3D objects.

The figures and components therein may not be drawn to scale. Variouscomponents of the figures described herein may not be drawn to scale.

DETAILED DESCRIPTION

While various embodiments of the invention have been shown and describedherein, it will be obvious to those skilled in the art that suchembodiments are provided by way of example only. Numerous variations,changes, and substitutions may occur to those skilled in the art withoutdeparting from the invention. It should be understood that variousalternatives to the embodiments of the invention described herein mightbe employed.

Terms such as “a,” “an” and “the” are not intended to refer to only asingular entity, but include the general class of which a specificexample may be used for illustration. The terminology herein is used todescribe specific embodiments of the invention, but their usage does notdelimit the invention. When ranges are mentioned, the ranges are meantto be inclusive, unless otherwise specified. For example, a rangebetween value1 and value2 is meant to be inclusive and include value1and value2. The inclusive range will span any value from about value1 toabout value2.

The term “adjacent” or “adjacent to,” as used herein, includes ‘nextto’, ‘adjoining’, ‘in contact with,’ and ‘in proximity to.’ In someinstances, adjacent to may be ‘above’ or ‘below.’

The term “between” as used herein is meant to be inclusive unlessotherwise specified. For example, between X and Y is understood hereinto mean from X to Y.

The term “operatively coupled” or “operatively connected” refers to afirst mechanism that is coupled (or connected) to a second mechanism toallow the intended operation of the second and/or first mechanism.

Three-dimensional printing (also “3D printing”) generally refers to aprocess for generating a 3D object. For example, 3D printing may referto sequential addition of material layer or joining of material layers(or parts of material layers) to form a 3D structure, in a controlledmanner. The controlled manner may include automated and/or manualcontrol. In the 3D printing process, the deposited material can betransformed (e.g., fused, sintered, melted, bound or otherwiseconnected) to subsequently harden and form at least a part of the 3Dobject. Fusing (e.g., sintering or melting) binding, or otherwiseconnecting the material is collectively referred to herein astransforming the material (e.g., powder material). Fusing the materialmay include melting or sintering the material. Binding can comprisechemical bonding. Chemical bonding can comprise covalent bonding.Examples of 3D printing include additive printing (e.g., layer by layerprinting, or additive manufacturing). 3D printing may include layeredmanufacturing. 3D printing may include rapid prototyping. 3D printingmay include solid freeform fabrication. 3D printing may include directmaterial deposition. The 3D printing may further comprise subtractiveprinting.

3D printing methodologies can comprise extrusion, wire, granular,laminated, light polymerization, or powder bed and inkjet head 3Dprinting. Extrusion 3D printing can comprise robo-casting, fuseddeposition modeling (FDM) or fused filament fabrication (FFF). Wire 3Dprinting can comprise electron beam freeform fabrication (EBF3).Granular 3D printing can comprise direct metal laser sintering (DMLS),electron beam melting (EBM), selective laser melting (SLM), selectiveheat sintering (SHS), or selective laser sintering (SLS). Powder bed andinkjet head 3D printing can comprise plaster-based 3D printing (PP).Laminated 3D printing can comprise laminated object manufacturing (LOM).Light polymerized 3D printing can comprise stereo-lithography (SLA),digital light processing (DLP), or laminated object manufacturing (LOM).

3D printing methodologies may differ from methods traditionally used insemiconductor device fabrication (e.g., vapor deposition, etching,annealing, masking, or molecular beam epitaxy). In some instances, 3Dprinting may further comprise one or more printing methodologies thatare traditionally used in semiconductor device fabrication. 3D printingmethodologies can differ from vapor deposition methods such as chemicalvapor deposition, physical vapor deposition, or electrochemicaldeposition. In some instances, 3D printing may further include vapordeposition methods.

The methods, apparatuses, software, and systems of the presentdisclosure can be used to form 3D objects for various uses andapplications. Such uses and applications include, without limitation,electronics, components of electronics (e.g., casings), machines, partsof machines, tools, implants, prosthetics, fashion items, clothing,shoes, or jewelry. The implants may be directed (e.g., integrated) to ahard, a soft tissue, or to a combination of hard and soft tissues. Theimplants may form adhesion with hard and/or soft tissue. The machinesmay include a motor or motor part. The machines may include a vehicle.The machines may comprise aerospace related machines. The machines maycomprise airborne machines. The vehicle may include an airplane, drone,car, train, bicycle, boat, or shuttle (e.g., space shuttle). The machinemay include a satellite or a missile. The uses and applications mayinclude 3D objects relating to the industries and/or products listedherein.

The present disclosure provides systems, apparatuses, software and/ormethods for 3D printing of a desired 3D object from a pre-transformedmaterial (e.g., powder material). The 3D object can be pre-ordered,pre-designed, pre-modeled, or designed in real time (e.g., during theprocess of 3D printing).

Pre-transformed material as understood herein is a material before ithas been transformed by an energy beam during the 3D printing process.The pre-transformed material may be a material that was, or was not,transformed prior to its use in the 3D printing process. Thepre-transformed material may be a solid, semi-solid, or liquid (e.g., asdisclosed herein). The pre-transformed material may be a particulatematerial (e.g., powder). The 3D printing method can be an additivemethod in which a first layer is printed, and thereafter a volume of apre-transformed material is added to the first layer as separatesequential layer (or parts thereof). Each additional sequential layer(or part thereof) can be added to the previous layer by transforming(e.g., fusing) a fraction of the pre-transformed material to form atransformed material as part of the 3D object. The transformed materialmay subsequently harden to form at least a portion of the 3D object. Thehardening can be actively induced (e.g., by cooling) or can occurwithout intervention (e.g., naturally).

The fundamental length scale (herein abbreviated as “FLS”) of theprinted 3D object can be at least about 50 micrometers (μm), 80 μm, 100μm, 120 μm, 150 μm, 170 μm, 200 μm, 230 μm, 250 μm, 270 μm, 300 μm, 400μm, 500 μm, 600 μm, 700 μm, 800 μm, 1 millimeter (mm), 1.5 mm, 2 mm, 5mm, 1 centimeter (cm), 1.5 cm, 2 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm,60 cm, 70 cm, 80 cm, 90 cm, 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, 50 m, 80 m,or 100 m. The FLS of the printed 3D object can be at most about 1000 m,500 m, 100 m, 80 m, 50 m, 10 m, 5 m, 4 m, 3 m, 2 m, 1 m, 90 cm, 80 cm,60 cm, 50 cm, 40 cm, 30 cm, 20 cm, 10 cm, or 5 cm. In some cases, theFLS of the printed 3D object may be in between any of theafore-mentioned FLSs (e.g., from about 50 μm to about 1000 m, from about120 μm to about 1000 m, from about 120 μm to about 10 m, from about 200μm to about 1 m, or from about 150 μm to about 10 m). The fundamentallength scale is the diameter, spherical equivalent diameter, diameter ofa bounding circle, and/or the largest of: height, width and length.

In some embodiments, the transformed material subsequently hardens toforms a hardened 3D object (herein “3D object”). Harden may comprisesolidify. Transform may comprise melt, sinter, adhere, attach,associate, join, affix, couple, unite, coalesce, consolidate, merge,unify, amalgamate, bind, merge, conjoin, consolidate, melt, unify, tack,or connect. Transform may comprise transform the physical state of atleast a portion of the pre-transformed material (e.g., from solid toliquid). The apparatuses, systems, software and/or methods describedherein may be utilized for the formation of a 3D object that is devoidof one or more auxiliary features. The apparatuses, systems, software,and/or methods described herein may be utilized for the formation of a3D object that is suspended (e.g., floats anchorlessly) in the materialbed, for example, during its formation. The apparatuses, systems,software, and/or methods described herein may be utilized for theformation of a 3D object that is suspended anchorlessly in the materialbed during its entire generation process. The apparatuses, systems,software and/or methods described herein may reduce the deformation ofone or more layers or parts thereof within the 3D object (e.g., upon itsformation and/or after its formation). The deformation may comprisebending, warping, arching, curving, twisting, balling, cracking,dislocating, or any combination thereof.

The FLS (e.g., width, depth, and/or height) of the material bed can beat least about 50 millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm, 100 mm,200 mm, 250 mm, 280 mm, 400 mm, 500 mm, 800 mm, 900 mm, 1 meter (m), 2 mor 5 m. The FLS (e.g., width, depth, and/or height) of the material bedcan be at most about 50 millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm,100 mm, 200 mm, 250 mm, 280 mm, 400 mm, 500 mm, 800 mm, 900 mm, 1 meter(m), 2 m or 5 m. The FLS of the material bed can be between any of theaforementioned values (e.g., from about 50 mm to about 5 m, from about250 mm to about 500 mm, from about 280 mm to about 1 m).

In an aspect described herein are methods, systems, and/or apparatusesfor generating a 3D object with a reduced degree of deformation (e.g.,substantially non-deformed). The 3D object can be devoid of one or moreauxiliary supports. The 3D object can be devoid of a mark indicating theprior presence of one or more auxiliary supports. The 3D object can bean extensive 3D object. The 3D object can be a large 3D object. The 3Dobject may comprise a large hanging structure (e.g., wire, ledge, orshelf). Large may be a 3D object having a fundamental length scale of atleast about 1 centimeter (cm), 1.5 cm, 2 cm, 10 cm, 20 cm, 30 cm, 40 cm,50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, 50 m,80 m, or 100 m.

In some aspects, the methods may comprise depositing a pre-transformedmaterial (e.g., adjacent to a platform), and transforming it to atransformed material. The deposited pre-transformed material may form amaterial bed. The material bed may be temperature controlled (e.g.,heated and/or cooled). In some instances, the material bed may be heatedto a temperature close to the transformation temperature of thepre-transformed material (e.g., powder) within the material bed. In someembodiments, at least a portion of the 3D object is heated. For example,the at least a portion of the 3D object may be heated prior todepositing a newly pre-transformed material on the at least a portion ofthe 3D object. The heating temperature may be to a temperature close tothe melting temperature of the material. The heating temperature (e.g.,of the material bed and/or of the at least a portion of the 3D object)may be to a temperature of at least about 100° C., 50° C., 10° C., or 5°C. lower (e.g., colder) than the melting point of the material. Thetransformed material may subsequently harden to form at least a portionof the generated 3D object. In some embodiments, the transformedmaterial is the hardened material. The transformed material may form atleast a portion of the generated 3D object. The 3D object may be formedfrom a pre-transformed material that underwent a transformation andsubsequent hardening to form a hardened material that is at least aportion of the 3D object. The 3D object may be formed by successiveaddition of material that may form successive layers of hardenedmaterial.

At times, the successive additions of a layer of hardened materialconnects to a previously formed one or more layers of hardened material(e.g., through transformation). At times, the successive additions of alayer of hardened material may comprise connecting it to an object(e.g., 3D object). The object may or may not be formed using a 3Dprinting methodology (e.g., as disclosed herein). The object maycomprise a sheet of material (e.g., metal sheet). The connection topreviously formed layers of hardened material (e.g., 3D plane) may causethe formed joined structure to deform. The deformation may arise whenthe formed structure lacks auxiliary support structure(s) during itsformation. The deformation may arise, when the formed structure floatsanchorlessly in the material bed during its formation. In someinstances, deposition of a second layer of hardened material on a planarobject (e.g., a bottom skin layer) reduces a radius of curvature of thejoint structure that is being formed (e.g., cause the joint structure towarp). FIG. 2 shows various radius of curvature examples. Withoutwishing to be bound to theory, FIGS. 1A-1C show examples of variousstages in the formation of a second layer on a 3D plane. An example of a3D plane (e.g., a bottom skin layer) is shown in FIG. 1A, a second layeris then deposited on the 3D plane as shown in the example of FIG. 1B. Asthe second layer hardens (e.g., cooled down) the second layer mayshrink, resulting in deformation of the formed joint structure (e.g.,bilayer) as shown in the example of FIG. 1C. The first layer (e.g.,shown in FIG. 1A) can be a 3D printed layer, a 3D plane, a layergenerated by other methodologies, or any combination thereof. The firstlayer can be a naturally formed layer.

The 3D object may comprise a hanging structure. The hanging structuremay be a plane like structure (referred to herein as “three-dimensionalplane,” or “3D plane”). A three-dimensional (3D) plane may have arelatively small width as opposed to a relatively large surface area.For example, the 3D plane may have a small height relative to a largehorizontal plane. The 3D plane may be planar, curved, or assume anamorphous 3D shape. The 3D plane may be a strip, a blade, or a ledge.The 3D plane may comprise a curvature. The 3D plane may be curved. The3D plane may be planar (e.g., flat). The 3D plane may have a shape of acurving scarf. The 3D object may comprise a wire.

In some embodiments, methods, systems, software and/or apparatusesdescribed herein reduce the degree of deformation (e.g., as compared toconventionally used 3D printing methodologies). The degree ofdeformation may be reduced by using a first layer that comprises anegative radius of curvature (e.g., negative warping). Additionally, orseparately, the degree of deformation may be reduced by using a firstcooling member (such as a heat-sink or a cooling plate). In someembodiments, the cooling member (e.g., heat-sink) is situated adjacent(e.g., above) to the exposed layer of the material bed. FIG. 5A shows anexample of a cooling member 513 situated above an exposed surface of thematerial bed 504. The cooling member can be introduced and/or pulledaway from a position adjacent (e.g., above) the exposed surface of thematerial bed (e.g., during the 3D printing). The introduction and/orretrieval of the cooling member may be done in relatively short amountof time relative to the time-scale of the 3D printing. For example,relative to the time-scale of hardened layer formation and/orpre-transformed layer deposition. A second layer of transformed materialcan be formed on a first layer of hardened material. The first layer ofhardened material may be suspended in the material bed (e.g., during the3D printing). The first layer of hardened material may be devoid of oneor more auxiliary supports. The cooling member may be introduced andretrieved adjacent to the material bed (e.g., during the formation ofthe second layer). In some embodiments, the amount of time at which thesecond layer is exposed to the cooling member correlates (e.g., equate)to a formation of (i) a cooled top surface of the second layer, and (ii)hot internal surface of the second layer.

FIG. 6A shows an example of a first layer of hardened material 611 in amaterial bed 610. The layer of hardened material may be formed by a 3Dprinting methodology, and/or by other approaches. The layer of hardenedmaterial can be a sheet of material. FIG. 6B shows an example of a firstlayer of hardened material 611, and a second layer of transformedmaterial that in the process of hardening (e.g., becoming a hardenedmaterial) 612, and section 613 designates a transformed material that ishardening (e.g., cooling) as represented by grayscale gradient of 613,wherein cold is represented by a darker gray shade, and hot by a lightergray shade. In some examples, the amount of time at which the secondlayer is exposed to the cooling member correlates (e.g., equates) to aformation of a hardened top surface of the second layer, and at leastsome transformed material that did not harden at the internal surface ofthe second layer. The amount of time at which the second layer isexposed to the cooling member may correlate to a formation of trappedheat between the top (e.g., exposed) surface of the second layer and thebottom surface of the first layer. The amount of time at which thesecond layer is exposed to the cooling member may correlate to aformation of a trapped heat between the top (e.g., exposed) surface ofthe second layer and the top surface of the first layer. FIG. 6B showsan example of a region of trapped heat in 613. In some instances, aportion of the heat from the transformed material that forms the secondlayer is evacuated from above (e.g., using the cooling member), andanother portion of the heat remains within the 3D object. The usage ofthe cooling member may form a relatively colder outer surface of thesecond layer, and a relatively hotter inner surface of the second layer.FIG. 6C shows an example of a region comprising a heat gradient 614 thatis trapped within the 3D object that has cooled layer portions (e.g.,615). In the example shown in FIG. 6C, colder material is represented bya darker gray shade, and hotter material is represented by a lightergray shade. The trapped heat region may extend to the bottom of the 3Dobject, or to a position above the bottom of the 3D object. The trappedheat region may comprise the bottom surface of the 3D object. Thetrapped heat region may comprise an internal region within the 3D objectand substantially not extend to the bottom surface of the 3D object. Insome embodiments, the bottom surface of the 3D object may be heated byat most about 50%, 40%, 30%, 20%, 10%, 5%, or 1% relative to the hottestregion within the 3D object. The bottom surface of the 3D object may beheated by at least about 50%, 40%, 30%, 20%, 10%, 5%, 1% or 0.5%relative to the hottest region within the 3D object. The bottom surfaceof the 3D object may be heated by any value between the afore-mentionedvalues (e.g., from about 1% to about 50%, or from about 1% to about 20%relative to the hottest region within the 3D object). The formation ofthe 3D object comprising the heat gradient may prevent warping of theformed 3D object (e.g., bilayer).

In some embodiments, the first cooling member may be a passive coolingmember (e.g., a slab comprising, for example, elemental metal or metalalloy). The passive first cooling member may be cooled by a secondcooling member. The second cooling member may be an active coolingmember. The active cooling member may include thermal conduction (e.g.,using a liquid). The first cooling member may be disposed within theenclosure. The second cooling member may be disposed outside of theenclosure. FIGS. 5A and 5B show examples of a first cooling member and asecond cooling member. FIG. 5A shows an example of a system andapparatuses (shown as a side view 500) where the first cooling member513 resides above the material bed 504 in which a 3D object 506 is beingformed with an energy beam 515. The first cooling member 513 is disposedwithin the enclosure 507, and the second cooling member 512 is notdisposed within the enclosure 507. The second cooling member 512 is anactive cooling member, for example, comprising one or more channels 517(shown as a vertical cross section thereof). The channels 517 can befilled with at least one coolant that flows within the second coolingmember 512 (e.g., and in the incoming hose 514 and outgoing hose 516).FIG. 5B shows an example of a system and apparatus (shown as a side view520) where the first cooling member 533 contacts the second coolingmember 532.

In some instances, the first layer (e.g., bottom skin) comprises anegative warping with respect to the platform (e.g., building platform)and/or the exposed surface of the material bed. Negative warping, asunderstood herein, comprises a convex structure relative to an exposedsurface of a material bed and/or platform. FIG. 2 shows an example oflayers that are positively warped (i.e., has a positive curvature),negatively warped (i.e., has a negative curvature), or non-warped (i.e.,has substantially zero curvature), depicted as a vertical cross section.For example, layer number 6 of object 212 is negatively warped (i.e.,has a negative curvature) with respect to the platform 218. In thelayered structure 212, layer number 6 has a curvature that is negative,as the volume (e.g., area in a vertical cross section of the volume)bound from the bottom of it to the platform 218 is a convex object 219.Layer number 5 of 212 has a curvature that is negative. Layer number 6of 212 has a curvature that is more negative (e.g., has a curvature ofgreater negative value) than layer number 5 of 212. Layer number 4 of212 has a curvature that is (e.g., substantially) zero. For example,layer number 6 of object 214 is positively warped (i.e., has a positivecurvature) with respect to the platform 218. Layer number 6 of 214 has acurvature that is positive. Layer number 6 of 212 has a curvature thatis more negative than layer number 5 of 212, layer number 4 of 212, andlayer number 6 of 214.

As understood herein, the radius of curvature, “r,” of a curve at apoint is a measure of the radius of the circular arc (e.g., FIG. 2, 216)which best approximates the curve at that point. The radius of curvatureis the inverse of the curvature. In the case of a 3D curve (also hereina “space curve”), the radius of curvature is the length of the curvaturevector. The curvature vector can comprise of a curvature (e.g., theinverse of the radius of curvature) having a particular direction. Forexample, the particular direction can be the direction towards theplatform (e.g., designated herein as negative curvature), or away fromthe platform (e.g., designated herein as positive curvature). Forexample, the particular direction can be the direction towards thedirection of the gravitational field (e.g., designated herein asnegative curvature), or opposite to the direction of the gravitationalfield (e.g., designated herein as positive curvature). A curve (alsoherein a “curved line”) can be an object similar to a line that is notrequired to be straight. A (straight) line can be a special case ofcurve wherein the curvature is substantially zero. A curve can be in twodimensions (e.g., vertical cross section of a plane), or in threedimension (e.g., curvature of a plane).

When a subsequent layer is deposited on the convex surface of the firstlayer, and is subsequently hardened, the convex surface may straighten.Without wishing to be bound to theory, the straightening may occur dueto contraction of the second layer upon hardening (e.g., solidifying).The second layer may adhere to the first layer. The adhered second layermay shrink upon hardening (e.g., cooling and/or solidifying). The firstlayer comprising the negative warpage (i.e., negative curvature) may begenerated as a single layer. The first layer may be a 3D plane that isnegatively curved. The 3D plane may be formed by 3D printing. The 3Dplane may be formed using other approaches. For example, the 3D planemay be a sheet of material. The 3D plane can be naturally found.Negatively warped layers and/or objects can be formed by variousmethods. Example for methods, software, systems and/or apparatuses forforming negatively warped layers and/or objects can be found in patentapplication number PCT/US16/34857 titled “THREE-DIMENSIONAL PRINTING ANDTHREE-DIMENSIONAL OBJECTS FORMED USING THE SAME” filed on May 27, 2016that is entirely incorporated herein by reference. Without wishing to bebound to theory: FIG. 3A shows an example of a first negatively warpedlayer 311. FIG. 3B shows an example of a layer of transformed material322 deposited on a negatively warped layer 321 before completely coolinglayer 322. FIG. 3C shows an example of a hardened (e.g., cooled) layerof transformed material 332 deposited on a negatively warped layer thathas been straightened 331 during the hardening (e.g., cooling) of thetransformed material 322 into 332. The first layer comprising thenegative warpage (e.g., negative curvature) may be generated from aplurality of sub-layers in a particular geometry, such that togetherthey may form a hardened structure comprising an average negative radiusof curvature of the hardened structure. FIG. 3D shows an example of ahardened structure 341 that is made of a plurality of sub layers andcollectively comprises an average negatively curved layer (e.g., astructure having an average negative curvature). FIG. 3E shows anexample of a layer of transformed material 352 that is deposited on ahardened structure formed of a multiplicity of sub layers 351 thatcollectively has an average negative curvature, wherein the layer 352 isnot completely cooled. FIG. 3F shows an example of a hardened (e.g.,cooled) layer of transformed material 362 deposited on a negativelywarped layer that has been straightened 361 during the hardening (e.g.,cooling) of the transformed material, which straightened layer comprisesthe plurality of layers from which it is composed (not shown).

Additionally, or separately, the degree of deformation may be reduced byusing a semi adhered layer. In some examples, a 3D object comprises twolayers (i.e., a first and second layer) of hardened material that areseparated by a gap-layer. The first and second layer may be (e.g.,substantially) planar (e.g., flat). At times, at least one of the twolayers may have a large radius of curvature (e.g., a radius of curvatureof at least about 20 cm, 30 cm, 40 cm, 50 cm, 80 cm, or 100 cm). Theradius of curvature may be any radius of curvature disclosed herein. Thefirst and second layers may be devoid of one or more auxiliary supports(e.g., anchors) during the 3D printing. In some embodiments, thegap-layer has a smaller height relative to the first and/or secondlayer. In some embodiments, the gap-layer has a larger height relativeto the first and/or second layer. The gap-layer may be less dense (e.g.,sparser) than the first layer of hardened material and the second layerof hardened material. The gap-layer may comprise non-transformedmaterial. For example, the gap-layer may comprise particulate material(e.g., powder). FIG. 4A shows an example of a layer of hardened material411 on which a layer of pre-transformed (e.g., powder) material 413 isdisposed. FIG. 4B shows an example of a first layer 421, a second layer422, and a gap-layer 423 that comprises pre-transformed material. Thegap-layer may comprise a multiplicity of gap-layers. The gap-layerswithin the multiplicity of gap layers may be of the same kind ofgap-layer, or of different kinds of gap-layer (e.g., as disclosedherein). The gap-layer may be subsequently transformed. In someembodiments, the gap layer can be lightly sintered. FIG. 4C shows anexample of a gap-layer that is (e.g., lightly) sintered in 433, wherethe layers 431 and 432 represent layers of hardened material. Thetransformation can include transforming (e.g., melting) the particularmaterial within the gap-layer at one or more positions to formrespective one or more connections between the two layers of hardenedmaterial. The one or more connections can comprise pillars or clumps.The one or more connections can be generated prior to, during, orsubsequent to, forming a lightly sintered structure. The one or moreconnections can be generated without forming a lightly sinteredstructure. The one or more positions (e.g., where the connections areformed) can be distributed along the gap-layer to entrap the particulatematerial. The one or more positions can be sequentially situated andgradually connect the first and second layer, for example, similar toclosing of a zipper. FIG. 4D shows and example of two layers of hardenedmaterial 441 and 442 that are separated by a gap that comprisespre-transformed and/or sintered material (e.g., porous hardenedmaterial) and sections transformed material (e.g., 443) that aredistributed within the gap and connect the first hardened layer 441 tothe second hardened layer 442. FIG. 4D shows an example of a gap-layerhaving connections 443. The gap-layer can be annealed (e.g., duringand/or after the 3D printing). The gap-layer can form a continuous or adiscontinuous layer of transformed material to connect the first andsecond layer of hardened material (e.g., 441 and 442). FIG. 4E shows andexample of two layers of hardened material 451 and 452 that areseparated by a gap that comprises pre-transformed material (e.g.,powder) 453 that is being transformed and optionally hardened (e.g.,454) within the gap. The various gradients of gray in 454 representdifferent temperatures, wherein a darker shade represents a material ofa cooler temperature, and a lighter shade represents material of ahotter temperature. FIG. 4F shows an example of a gap-layer with atransformed and optionally hardened layer of material 463. FIG. 4F showsand example of two layers of hardened material 461 and 462 that areseparated by a gap that comprises transformed and optionally hardenedmaterial (e.g., 463).

In some instances, the pre-transformed material (e.g., in the materialbed) may be transformed via heat. The heat can be generated by at leastone energy beam, an overlapping array or energy beams (e.g., LED arrayor laser array), a lamp, a radiator, any radiative heat source, or anycombination thereof. FIG. 7 shows an example of a system andapparatus(es) 700 (shown as a side view) comprising an energy beam 701that transforms a portion of the material bed 704 into a 3D object 706.In this example, the 3D object is floating anchorlessly (i.e., issuspended) within the material bed 704. FIG. 7 shows an example of aheat sink 713 disposed above the material bed, which material bed isdisposed on a building platform comprising a base 702 and a substrate709 that is connected to a vertical actuator 712 (e.g., elevator). FIG.7 shows an example of sealants 703 that prevent the pre-transformedmaterial from spilling from the material bed 704 to the bottom 711 ofthe enclosure 707, wherein an interior 715 of the enclosure has anatmosphere comprising a gas. In some embodiments, the enclosureincorporates a cooling member (e.g., 713) that can be translatable(e.g., during the 3D printing). The sealants (e.g., seals) can compriseO-rings, rubber seals, metal seals, load-locks, or bellows on a piston.

In some embodiments, negative warping is formed by deep area heating(e.g., FIG. 11F) of a 3D object without melting. FIGS. 11A-11E showexamples of various stages in forming a negatively warped object (e.g.,object with negative curvature) using a deep area heating methodologydepicted as a vertical cross section. In this methodology, a portion ofa layer of hardened material (e.g., FIG. 11A, 1111) may be heated toform a heated portion (e.g., FIG. 11B, 1112) and one or more non-heatedportions (e.g., FIG. 11B, 1111 a and 1111 b). In the examples shown inFIGS. 11A-F, a darker shade presents a hotter area, and a brighter shaderepresents a cooler area. The heated portion may not border the rim ofthe layer of hardened material. For example, the heated portion may bein the center of the to-be-bent layer of hardened material. The heatedportion may expand (e.g., during the heating). Consequently, theexpanded heated portion may compress the colder portions (e.g., 1111 aand 1111 b). Without wishing to be bound to theory, the heated portionmay be subject to tensile stress. The top (e.g., closer to the exposedsurface) of the heated portion may be transformed (e.g., molten) (e.g.,FIG. 11C, 1114). The height of the molten portion may be at least about1%, 5%, 10%, 15%, 20%, 25%, or 30% of the total height of the layer ofhardened material. The height of the molten portion may be at most about1%, 5%, 10%, 15%, 20%, 25%, or 30% of the total height of the layer ofhardened material. The height of the molten portion may be any valuebetween the abovementioned values with respect to the total height ofthe layer of hardened material (e.g., from about 1% to about 30%, fromabout 10% to about 20%, or from about 5% to about 25%). The transformed(e.g., molten) portion may further expand (e.g., more than the expansionof the heated portion). Without wishing to be bound to theory, thefurther expansion may exert contractile stress on the previously heatedportion of the layer. The heated portion (e.g., FIG. 11C, 1113) maycomprise a sub-portion that is subject to contractile stress (e.g., FIG.11D, 1115). This method may form a portion of the 3D object in which thestress profile (e.g., gradient) comprises relatively more contractilestress at its top (towards the exposed surface) than at its bottom (awayfrom the exposed surface). The bottom of the portion may be thereforesubject to a tensile stress. Consequently, the heated area (e.g., FIG.11D, 1114-1116) may force the two sides of the heated area (e.g., FIG.11D, 1111 a and 1111 b) to bend towards the platform and form bent areas(e.g., FIG. 11E, 1117 a and 1117 b). Thus, the layer of hardenedmaterial may form a negatively warped structure upon cooling (e.g.,depicted in FIG. 11E). FIG. 11E 1114-1116 correlate to FIG. 11D1114-1116 respectively. The layer of hardened material may form a 3Dobject that is susceptible to the desired negatively warped deformation(e.g., FIG. 11E). In some embodiments, the transformed top layer 1114may be removed (e.g., ablated) at least in part (e.g., entirely). Whenthe transformed top layer is removed, the tensile-contractive stressgradient is enhanced. FIG. 11F shows an example where the transformedlayer is removed (e.g., 1118). FIG. 11F 1115-1116 correlate to FIG. 11D1115-1116 respectively.

The bottom of the portion of the layer of hardened material may bedirected away from the exposed surface of the hardened material, and/ortowards the platform. The bottom of the portion of the layer of hardenedmaterial may be the surface of the hardened material directed away fromthe exposed surface of the hardened material, and/or towards theplatform. The top of the portion of the layer of hardened material maybebe directed towards, or be, the exposed surface of the hardenedmaterial.

The heated portion (e.g., 1112) and/or the transformed (e.g., molten)portion (e.g., 1114) may be formed by an energy beam. The energy beammay travel along a path. The path may be a predetermined path. The pathmay be predetermined by the controller. In some embodiments, thecontroller regulates and/or directs the energy beam (e.g., the path ofthe energy beam) directly and/or through one or more apparatuses. Forexample, the controller may direct a scanner that directs the energybeam along at least one path.

Control may comprise regulate, manipulate, restrict, direct, monitor,adjust, or manage.

The 3D object to be melted may have a rectangular cross section (e.g.,vertical and/or horizontal). The rectangle can be square or non-square(e.g., oblong). The rectangle can have an aspect ratio of width tolength (W:L) of at least about 1:1, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:50,or 1:100. The rectangle can have an aspect ratio of width to length(W:L) of at most about 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, 1:50, or 1:100.The rectangle can have an aspect ratio of width to length (W:L) betweenany of the afore mentioned values (e.g., from about 1:1 to about 1:100,from about 1:1 to about 1:10, or from about 1:2 to about 1:50). Therectangular cross section may have a long side (e.g., FIG. 15A, 1515)and a short side (e.g., FIG. 15A, 1514). The path may substantiallytravel along, perpendicular, or at an angle relative to the long side ofthe rectangular cross section. FIG. 15A shows an example of arectangular cross section of a 3D object, a portion of which is heatedby an energy beam that travels along a path 1512 which may besubstantially aligned parallel to the long side (e.g., the hatching areais in the direction parallel to the long side). FIG. 15B shows anexample of a rectangular cross section of a 3D object, a portion ofwhich is heated by an energy beam that travels along a path 1522 whichis substantially aligned parallel to the short side (e.g., the hatchingarea is in the direction parallel to the short side). The path (e.g.,hatching) may be a connected path or a disconnected path (e.g.,comprises disconnected path sections). The path may comprise parallelsection, non-parallel sections, angular sections, curved sections, orirregular sections. FIG. 15C shows an example of a path 1532 thatcomprises irregular sections. In some embodiments, as the energy beamtravels along the path in a position distant from one of the edges of alayer, the edge may deform (e.g., wrap upwards or wrap downwards). Theposition distant from one of the edges (e.g., 1511 or 1512) may be thecenter of the layer (e.g., where the energy beam travels along the path1512). In some embodiments, depending on the path direction, theposition distant from one of the edges of a layer may deform at acertain position (e.g., wrap upwards or wrap downwards).

The path of the energy beam may comprise a raster, a vector, or anycombination thereof. For example, the path of the energy beam (e.g., thefirst path) may be a vector. The path of the energy beam may beoscillating. For example, the path of the energy beam may comprise azigzag, wave (e.g., curved, triangular, or square), or curved pattern.The curved wave may be a sine or cosine wave. The path of the energybeam may comprise a sub-pattern. The sub-pattern may have any of theenergy beam patterns disclosed herein. FIG. 16 shows an example of apath 1611 of an energy beam comprising a zigzag sub-pattern (e.g., 1612shown as an enlargement of a portion of the path 1611). FIG. 16 shows anexample of a path 1621 of an energy beam comprising a curved sub-pattern1622. The sub-path may form the path of the energy beam. The sub-pathmay be a small path that forms the large path. The amplitude of thesub-path may be smaller than the amplitude and/or scale of the energybeam path. The sub-path may be a component of the energy beam path. Thepath that the energy beam follows may be a predetermined path. The paththat the energy beam follows may be connected or disconnected. Forexample, FIG. 1611 shows a connected path. For example, FIG. 16, 1621shows a disconnected path. The connected path can be connected withcurved connectors or non-curved connectors. In some examples, the entirepath may be substantially non-curved. In some instances, the entire pathmay be substantially curved. FIG. 16 shows an example of a connectedpath 1611 with curved connectors (e.g., 1613). Each of the vectorialpath sections may be formed of a sub path (e.g., zigzag or curved). Thenon-curved connectors can form a right angle, or another angle. Thenon-curved connected paths may form a rectangular connected path. FIG.16 shows an example of a connected path 1631 with non-curved (e.g.,right angled) connectors (e.g., 1633). The non-connected path maycomprise of vectorial path sections. At least two of the vector pathsections may be pointed in the same direction. FIG. 16 shows an exampleof non-connected path 1641 that comprises vector path sections numbered1 to 5, all of which point to the same direction. FIG. 16 shows anexample of non-connected path 1621 that comprises vector path sectionsnumbered 1 to 5, of which at least vector sections 1 and 2 point todifferent directions. A 3D model and/or algorithm may predetermine thepath. The 3D model may be predetermined (e.g., by a processor, by anindividual, by a computer, by a computer program, by a drawing, by astatute, or by any combination thereof).

The path can comprise successive lines (e.g., vector path sections). Thesuccessive lines may touch each other. The successive lines may overlapeach other in at least one point. The successive path lines maysubstantially overlap each other. The successive lines may be spaced bya first distance (e.g., hatch spacing). FIG. 16 shows an example of ahatch spacing 1643. The first distance may vary depending on theposition of the generated hardened material within the 3D object. Thehatch spacing (i.e., distance between disconnected sections of the path)may be at least 500 micrometers (μm), 400 μm, 300 μm, 200 μm, 100 μm, 90μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, 5 μm, or 1μm. The hatch spacing may be at most 500 micrometers (μm), 400 μm, 300μm, 200 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20μm, 10 μm, 5 μm, or 1 μm. The hatch spacing may be any value between theafore-mentioned first distance values (e.g., from 500 μm to 1 μm, from100 μm to 20 μm, from 60 μm to 5 μm). In some examples, an angle betweensuccessive path lines is varied.

In some instances, the direction of the energy beam path (e.g.,direction of the hatching) determines the curvature of the 3D object,the bottom surface of the 3D object, and/or the top surface of the 3Dobject. In some instances, the direction of the energy beam pathdetermines the curvature of the 3D object. The curvature of the 3Dobject may comprise the bottom surface of the 3D object, and/or the topsurface of the 3D object. The direction of the energy beam path may bethe direction of the hatchings. The degree and/or direction of curvatureof the 3D object may be influenced by one or more characteristics of thematerial forming the 3D object. The one or more characteristics of thematerial may comprise the transformation (e.g., melting) temperature orthe elastic (e.g., Young's) modulus. The degree and/or direction ofcurvature of the 3D object may be influenced by the size of the meltpools formed by the energy beam. FIG. 8A shows an example of successivemelt pools in a 3D object. The degree and/or direction of curvature(e.g., positive, substantially zero, or negative) of the 3D object maybe influenced by the depth of heat penetration (e.g., of the energybeam) into the 3D object (e.g., depth of 1114 in FIG. 11C). The degreeand/or direction of curvature of the 3D object may be influenced by thedirection of the path portions with respect to the direction of thegreater path.

In another aspect a method for forming a 3D object comprises: providinga negatively warped layer of hardened material disposed in a materialbed and transforming at least a portion of the material bed into atransformed material that is coupled (e.g., attaches) to the negativelywarped layer. The transformed material may form a hardened material aspart of the 3D object. For example, the transformed material maysubsequently harden into a hardened material as part of the 3D object.

In another aspect a method for forming a 3D object comprises: providinga first structure having a bottom surface with a first curvature that isnegative, which structure comprises a hardened (e.g., solid) materialand is disposed in a material bed adjacent to a platform; andtransforming at least a portion of the material bed (e.g., powder bed)into a transformed material that is coupled to the top of the firststructure to form a second structure (that includes both the transformedmaterial and the first structure), which transformed material hardens(e.g., solidifies) into a hardened (e.g., solid) material as part of the3D object, wherein a bottom surface of the second structure has a secondcurvature that is greater than the first curvature, wherein the firstcurvature is negative when a volume bound from the bottom surface to theplatform is a convex object, which bottom surface is disposed above theplatform, wherein bottom faces the platform, wherein top faces away fromthe platform.

In some embodiments, the curvature of all the layers within the 3Dobject is from at most about 0.02 millimeters⁻¹ (i.e., 1/millimeters).In some embodiments, the layers within the 3D object are (e.g.,substantially) planar (e.g., flat). The curvature can be at most about−0.05 mm⁻¹, −0.04 mm⁻¹, −0.02 mm⁻¹, −0.01 mm⁻¹, −0.005 mm⁻¹, −0.001mm⁻¹, substantially zero mm⁻¹, 0.001 mm⁻¹, 0.005 mm⁻¹, 0.01 mm⁻¹, 0.02mm⁻¹, 0.04 mm⁻¹, or 0.05 mm⁻¹. The curvature can be any value betweenthe aforementioned curvature values (e.g., from about −0.05 mm⁻¹ toabout 0.05 mm⁻¹, from about −0.02 mm⁻¹ to about 0.005 mm⁻¹, from about−0.05 mm⁻¹ to substantially zero, or from about substantially zero toabout 0.05 mm⁻¹). The curvature may refer to the (e.g., average or mean)curvature of a surface. The surface can be of the layer of hardenedmaterial (e.g., first layer). The surface may be of the 3D object (orany layer thereof).

In another aspect, a method for forming a 3D object comprises: forming afirst layer of hardened material in a material bed comprisingpre-transformed material; disposing an upper layer of pre-transformedmaterial on the first layer of hardened material; and generating asecond layer of hardened material from at least a portion of the upperlayer of pre-transformed material, wherein the first layer of hardenedmaterial is separated from the second layer of hardened material by agap, wherein the gap comprises a material that is less dense than thefirst layer of hardened material and the second layer of hardenedmaterial. The less dense material can comprise pre-transformed material(e.g., powder). For example, the less dense material can comprise apowder or a sintered powder (e.g., lightly sintered powder). (e.g., seeFIGS. 4A-4F)

The platform may comprise a base, substrate, or a bottom of theenclosure. The platform may be a building platform. The platform may beadjacent to (e.g., above) where the 3D object is generated. Above may bein a direction opposing the direction of the field of gravity. Above maybe in a direction opposite to the building platform. In someembodiments, the method may further comprise after the operation ofdisposing an upper layer of pre-transformed material and before theoperation of generating a second layer of hardened material from atleast a portion of the upper layer, disposing a leveled (e.g., planar)layer of pre-transformed material on the first layer of hardenedmaterial. The gap may comprise portions of hardened material andportions that include pre-transformed material and/or sintered powdermaterial. At least some of the portions (e.g., all of the portions) maybe distributed (e.g., evenly) across the gap. At least some of theportions (e.g., all of the portions) may be concentration (e.g., evenly)within the gap (e.g., to the first and/or second layer of hardenedmaterial). The method disclosed herein may further comprise transformingthe material within the gap to form a transformed material as part ofthe 3D object. The transformed material may subsequently harden into ahardened material as part of the 3D object. (e.g., see FIG. 4F)

In another aspect, a method for forming a 3D object comprises: forming afirst layer of material in a material bed comprising pre-transformedmaterial, which first layer of material comprises a hardened material;disposing an upper layer of pre-transformed material on the first layerof material; generating a second layer of material comprisingtransformed material from at least a portion of the upper layer ofpre-transformed material; and cooling the second layer of material suchthat the top surface of the second layer of material is colder than itsbottom surface. The top surface of the second layer can be an exposedsurface. The bottom surface of the second layer may contact the firstlayer of material. In some embodiments, the transformed materialsubsequently hardens. In some embodiments, the transformed materialcomprises hardened material.

In another aspect, a method for forming a 3D object comprises: forming ahardened material in a material bed comprising pre-transformed material;disposing a layer of pre-transformed material on the hardened material;transforming (e.g., melting) a portion of the layer to form atransformed (e.g., molten) portion; hardening the exposed surface of thetransformed portion while the interior of the transformed portionremains transformed (e.g., non-hardened. E.g., molten); and hardening(e.g., solidifying) the transformed portion to form at least a portionof the 3D object.

In the operation of hardening the transformed portion, the method mayfurther comprise cooling the molten portion for the hardening. Themethod may reduce or preserve a curvature (e.g., value of the curvature)of at least one surface (e.g., all surfaces) of the 3D object. Themethod may reduce or preserve a curvature of at least one layer (e.g.,all layers) of the 3D object. The method may reduce the curvature of atleast one layer of the 3D object such that it may comprise a positivecurvature, negative curvature, or substantially zero curvature. Themethod may reduce the curvature of at least one surface of the 3D objectsuch that it may comprise a positive curvature, negative curvature, orsubstantially zero curvature.

In another aspect, a method for forming a 3D object comprises: forming afirst (layer of) hardened material in a material bed comprisingpre-transformed material; disposing a layer of pre-transformed materialon the first hardened material; transforming (e.g., melting) a portionof the layer of pre-transformed material and a portion of the first(layer of) hardened material to form a transformed portion and aremainder (e.g., of the first hardened material); and hardening thetransformed portion to form a second hardened material; and plasticallydeforming a region comprising (i) a portion of the second hardenedmaterial, and (ii) a portion of the remainder of the first (layer of)hardened material that is bordering the second hardened material,wherein the region comprises an exposed surface and an interior, whichexposed surface ceases to plastically deform before the interior ceasesto plastically deform, wherein the hardening forms at least a portion ofthe 3D object. (See FIGS. 11A-11F)

The transforming (e.g., melting) may be transforming together a portionof the layer of pre-transformed material and a portion of the first(layer of) hardened material to form a transformed (e.g., molten)portion. The hardening may be solidifying. The method disclosed hereinmay control the curvature of at least one surface of the 3D object. Themethod disclosed herein may control the curvature of at least onesurface of a layer of the 3D object. The method disclosed herein maycontrol the curvature of at least one layer of the 3D object. Duringformation, the 3D object may be suspended anchorlessly in the materialbed (e.g., during its formation). The 3D object may comprise auxiliarysupports or be devoid of auxiliary supports (e.g., during itsformation). The auxiliary supports may be suspended (e.g., anchorless)in the material bed (e.g., during formation of the 3D object). Themethod disclosed herein may reduce (or preserve) the curvature of atleast one layer and/or surface of the 3D object. The method disclosedherein may reduce (or preserve) the curvature of at least one layersurface of the 3D object. The methods disclosed herein may result in theat least one surface of the 3D object having a positive curvature,negative curvature, or substantially zero curvature. In someembodiments, the hardening operation occurs before the deformingoperation. The method disclosed herein may further comprise after thehardening operation and before a completion of the plastic deformation,heating and/or cooling the second hardened material. The cooling may becooling from above the exposed surface (e.g., using a cooling member).

FIG. 11A shows an example of a 3D hardened material structure 1111 in amaterial bed 1110 comprising pre-transformed material (e.g., powderbed). FIG. 11B shows an example of a heated portion 1112 within a 3Dhardened material structure, which comprises two sections that have notbeen heated (e.g., 1111 a and 1111 b). The heating can be performed byany one or more energy source disclosed herein (e.g., conductive heatsource and/or energy beam). The heated portion can be centered or notcentered with respect to a cross section of the 3D object (e.g.,horizontal, vertical, or angular). The heated portion can be in themiddle of the 3D object, or a layer thereof. The heated portion can beon the side of the 3D object. In some embodiments, the heated portion isnot at the side of the 3D object. At times, the heated portion does notborder a side portion of the 3D object (e.g., with respect to thebuilding platform). At times, the heated portion is situated at adistance from the opposing sides of the 3D object. At times, the heatedportion is situated (e.g., substantially) symmetrically at a distancefrom the opposing sides of the 3D object with respect to at least onecross section (e.g., horizontal, vertical, or angular). Substantially isrelative to the intended purpose of the 3D object. FIG. 11B shows anexample where the heated portion 1112 is situated (e.g., substantially)symmetrically at the center of the 3D object with respect to a verticalcross section of the 3D object (e.g., layer thereof), at an equaldistance from each of the opposing sides of the 3D object (e.g., 1119,1120). At times, the heated portion is situated unsymmetrically atunequal distances from either opposing side of the 3D object, withrespect to at least one cross section (e.g., horizontal, vertical, orangular). FIG. 11C shows an example of a transformed (e.g., molten)portion 1114 within the heated portion, depicting the remainder of theheated portion that did not transform in 1113. FIG. 11D schematicallyshows a region of higher temperature 1115 between the transformedportion 1114 and the non-transformed heated portion 1113, which 1115comprises non-transformed material that is at a temperature that ishigher than the temperature in 1116. FIG. 11E schematically shows theresult of the shown in FIG. 11C and FIG. 11D, as the 3D objectplastically deforms. The exposed surface of the transformed (e.g.,molten) portion (e.g., 1114) may be smaller, or (e.g., substantially)similar to the exposed surface of the heated portion (e.g., 1112). Theexposed surface of the transformed portion may be contained within theexposed surface of the heated portion. The transformation and/or heatingof the hardened material may induce mechanical deformation of the 3Dobject. The transformation and/or heating of the hardened material mayinduce elastic and/or plastic deformation of the 3D object. Thetransformation and/or heating of the hardened material may inducefatigue (e.g., material fatigue such as metal fatigue) in the 3D object.The transformation and/or heating of the hardened material may inducecompressive and/or tensile stress in the 3D object. The transformationand/or heating of the hardened material may induce reversible and/orirreversible deformation of the 3D object.

The plastically deformed object can optionally be cooled from the top.The plastically deformed object can be cooled using the cooling memberdisclosed herein. The cooling may be a quick cooling by the coolingmember, or can be continuous and/or prolonged cooling. The quick coolingmay comprise introducing and quickly removing the cooling member from aposition adjacent (e.g., above) the transformed (e.g., molten) area(e.g., 1114). Quickly may be measured relative to the hardening of theinterior of the transformed area. Quickly may allow the interior of thetransformed area to remain transformed, whereas the exposed surface ofthe transformed area may harden. Quickly may allow the interior of themolten area to remain molten, whereas the exposed surface of the moltenarea may solidify.

The methods disclosed herein may comprise a material (e.g., of thepre-transformed material, of the material bed, of the hardened material,or any combination thereof) that conducts heat. The material may be suchthat the heat conduction and/or absorption of the hardened (e.g., solid)material is more efficient than that of the pre-transformed material(e.g., powder material). In some examples, the transformed portion(e.g., before or after its at least partial hardening) may be removed.The removal may comprise erosion, vaporization, chipping, or ablation.The removal may comprise a mechanical, optical, or chemical removal. Theablation may comprise directing an energy beam to the transformedportion (e.g., before or after its at least partial hardening). Theenergy beam may be any energy beam disclosed herein. The energy beam maybe the same, or a different energy beam that formed the molten portion(e.g., 1114). The energy beam may be the same, or a different energybeam that formed the heated portion (e.g., 1112). The heated portion maybe formed by an energy beam or by a radiative energy source. The energybeam forming the heated portion may be the same or different than theone forming the molten portion. FIG. 11F shows an example of a removedportion (1118) of the heated layer (e.g., 1112), resulting in heatedportions 1116 and 1115 forming a portion of the 3D object.

The material may be such that the heat may dissipate and/or transferthrough the hardened material in greater amount than thorough thepre-transformed form (e.g., powder) of that material. The material maybe such that the heat may thermally equilibrate in preference throughthe hardened material as compared to the pre-transformed form of thatmaterial. The material may have a characteristic wherein the heat maydissipate and/or transfer through the hardened (e.g., solid) material ingreater amount than thorough a powder of that material. The material maybe such that the heat may thermally equilibrate in preference throughthe hardened material as compared to the powder of that material. Moreefficient may refer to more efficient in time (e.g., quicker).

In some aspects disclosed herein is a 3D object (e.g., formed by a 3Dprinting process) that comprises one or more layer portions comprisingsuccessive solidified melt pools of a material, wherein the 3D objectcomprises a surface, and interior, and a grain structure. In that 3Dobject, the grain structure closer to the surface may be indicative of ahigher solidification rate than the grain structure in the interior. Thegrain structure may comprise a melt pool. For example, the grainstructure may be smaller (e.g., of a smaller volume or smaller FLS) at aposition closer to or at to the surface, as compared to the size of thegrain structure in the interior. The solidification may comprisecrystallization. The grain structure may be a microstructure. The grainstructure may be a metallurgical structure (e.g., planar structure,cellular structure, columnar dendritic structure, or equiaxed dendriticstructure).

In some aspects disclosed herein is a 3D object (e.g., formed by a 3Dprinting process) comprises one or more layer portions comprisingsuccessive solidified melt pools of a material, wherein the 3D objectcomprises a surface, an interior, and metallurgical microstructure(e.g., dendrites and/or cells), wherein the metallurgical microstructureat a position closer to or at the surface are indicative of a higher(e.g., quicker) solidification rate than the metallurgicalmicrostructure in the interior. The spacing between the metallurgicalmicrostructures may be smaller at a position closer to or at thesurface, as compared to the spacing of the (e.g., respective)metallurgical microstructure in the interior. The overall size of themetallurgical microstructure may be smaller at a position closer to orat the surface, as compared to the overall size of the (e.g.,respective) metallurgical microstructure in the interior (e.g.,indicating quick solidification). The 3D object disclosed herein may bedevoid of an auxiliary support feature or auxiliary support feature markthat is indicative of a presence or removal of the auxiliary supportfeature.

In another aspect, a method for forming a 3D object comprises:generating a first hardened material in an pre-transformed material beddisposed adjacent to a platform in an enclosure, which first hardenedmaterial comprises a bottom surface facing towards the platform; heatinga portion of the first hardened material to form a heated portion;transforming (e.g., melting) a portion of the top of the heated portionto form a transformed portion; and hardening the transformed portion toform a second hardened material that comprises a bottom surface facingtowards the platform. In some examples, the bottom surface of the firsthardened material has a first curvature that is of a higher value than asecond curvature of the bottom surface of the second hardened material.The bottom surface may have a negative curvature when a volume boundfrom the bottom surface to the platform is a convex object, which bottomsurface is disposed above the platform. The exposed surface of portionof the transformed portion may be contained within the exposed surfaceof the heated portion. The exposed surface of the molten portion may besmaller than an exposed surface of the heated portion. The heatedportion may not comprise the rim of the layer of hardened material. Themethod may further comprise removing a portion of the molten portion.The removed portion may comprise the exposed surface of the moltenportion. The method may further comprise removing a portion of theheated portion. The removal may comprise using an energy beam. The layerof hardened material may or may not be anchored to the enclosure inwhich the 3D object is formed (e.g., to the platform) during itsformation. The layer of hardened material may or may not compriseauxiliary supports during the formation of the 3D object.

In another aspect, a method for forming a 3D object comprises:generating at least a portion of a 3D object from a material bed;cooling the material bed using a first cooling member disposed withinthe enclosure; moving the first cooling member; and cooling the firstcooling member using a second cooling member that is disposed outside ofthe enclosure. The material bed may be disposed on a platform within anenclosure. Above may refer to a direction away from the platform and/oropposite to the direction of the gravitational force. The cooling membermay be disposed adjacent to the material bed. In some examples, thecooling member may be disposed above, to the side, or below the materialbed. For example, the cooling member may be disposed above an exposedsurface of the material bed. (See FIG. 5A).

The first cooling member may be disposed along the path of an energybeam that is used in generating the 3D object. The first cooling membermay be disposed in an isolated atmosphere. The material bed may comprisea material that is susceptible to oxygen and/or humidity. The materialbed may comprise an explosive material. The isolated atmosphere maycomprise a gas (e.g., as disclosed herein). For example, the isolatedatmosphere may comprise an inert gas. The first cooling member and thematerial bed may be disposed in the isolated atmosphere. The firstcooling member may be disposed in a first atmosphere, and the secondcooling member may be disposed in a second atmosphere. The firstatmosphere may be (e.g., substantially) similar to the secondatmosphere. The first atmosphere may be different than the secondatmosphere. The second cooling member may be disposed in an ambientatmosphere. The cooling of the first cooling member may comprisecontacting the first cooling member with the second cooling member(e.g., FIG. 5B). The contact between the first and second coolingmembers may be indirect (e.g., through a surface such as the surface ofthe enclosure). The indirect contact may comprise one or moreintervening surfaces between at least one surface of the first coolingmember and at least one surface of the second cooling member. The one ormore intervening surfaces may include the coating of the enclosure,and/or the walls of the enclosure. The contact between the first and thesecond cooling member may be direct. The direct contact may comprisecontacting at least one surface of the first cooling member with atleast one surface of the second cooling member. The first cooling membermay be passive. The passive cooling member may be a part (e.g., slab) ofmaterial. The passive cooling member may exclude active removal of heat(e.g., using a motor). The second cooling member may be actively cooled.The second cooling member may comprise a heat exchanger. The coolingmember (e.g., first or second) may comprise a thermostat. The coolingmember (e.g., first and/or second) may comprise heat control. Each ofthe cooling members may have its own heat control and/or sensor (e.g.,temperature sensor). At times, both cooling members may have a jointcontroller and/or sensor (e.g., temperature sensor). In someembodiments, both the first and the second cooling member are activelycooled. In some embodiments, both the first and the second coolingmember are passive. (See FIGS. 5A-5B and 18A-18B).

The first cooling member may be translatable. In some embodiments, thesecond cooling member may be translatable. The second cooling member maybe stationary. The stationary cooling member may have one or more partsthat are translatable and/or exchangeable. The first cooling member orany parts thereof may be exchangeable. The second cooling member maycomprise translatable coolant. The second cooling member may compriseone or more coolants that travel from a position adjacent to the firstcooling member and away from the position adjacent to the first coolingmember. When the coolants move away from the position adjacent to thefirst cooling member, the coolants may remove at least a portion of theenergy of the first cooling member away from the first cooling member.The method disclosed herein may further comprise translating the firstcooling member to a position adjacent to the second cooling member. hemethod may further comprise attracting the first cooling member to thesecond cooling member. The attraction may comprise mechanically bringingthe first cooling member to a position adjacent to the second coolingmember. The attraction may comprise generating a force that attracts thefirst cooling member to the second cooling member. The force maycomprise magnetic, hydraulic, or electric force. In some embodiments,cooling the material bed using the first cooling member comprisesremoving a percentage of heat from an exposed surface of the materialbed. The percentage may be at least about 10%, 20%, 30%, 40%, 50%, 60%,70%, 80%, or 90%. The percentage may be any percentage between theabovementioned percentages (e.g., from about 10% to about 90%, fromabout 30% to about 90%, from about 30% to about 50%, or from about 50%to about 90%).

In another aspect, a method for forming a 3D object comprises: using anenergy beam to transform at least a portion of a material bed to form atleast a portion of the 3D object; measuring one or more temperatures atone or more points adjacent to (or on) the at least a portion of the 3Dobject in real time during the 3D printing; and controlling the energybeam with at least one processing unit based on the measuredtemperatures. The processing unit may comprise at least 3 Tera floatingpoint operations per second according to a benchmark. The control of theenergy beam with the processing unit may be (e.g., further) based on ageometry of the at least a portion of the 3D object. The benchmark maycomprise a mathematical, graphical, or encryption benchmark. Theprocessing unit may comprise parallel processing. The processing unitmay comprise at least 8 billion transistors. The area of the processingunit may be at most about 600 mm². The processing unit may comprise atleast 1000 cores. The processing unit may comprise a memory bandwidth ofat least 100 Giga bytes per second. The processing unit may comprise amemory clock speed of at least 5 Giga bits per second. The controllingmay be based on at least one control mechanism. At times, the controlmechanism may exclude feedback from the structure of at least a portionof the generated 3D object. Sometimes, the control mechanism may includefeedback from the structure of at least a portion of the generated 3Dobject. The controlling may be based on a control mechanism comprisingtaking into account a generic geometric section (e.g., a primitive) thatis similar to a portion of the 3D object. The controller may comprise aprocessing unit. The controller may comprise a computer system. FIG. 14schematically shows an example of a computer system 1400 that isprogrammed or otherwise configured to facilitate the formation of a 3Dobject according to the methods provided herein.

In some embodiments, the material (e.g., pre-transformed, transformedand/or hardened) comprises elemental metal, metal alloy, ceramics, or anallotrope of elemental carbon. The allotrope of elemental carbon maycomprise amorphous carbon, graphite, graphene, diamond, or fullerene.The fullerene may be selected from the group consisting of a spherical,elliptical, linear, and tubular fullerene. The fullerene may comprise abuckyball or a carbon nanotube. The ceramic material may comprisecement. The ceramic material may comprise alumina. The material maycomprise sand, glass, or stone. In some embodiments, the material maycomprise an organic material, for example, a polymer or a resin. Theorganic material may comprise a hydrocarbon. The polymer may comprisestyrene. The organic material may comprise carbon and hydrogen atoms.The organic material may comprise carbon and oxygen atoms. The organicmaterial may comprise carbon and nitrogen atoms. The organic materialmay comprise carbon and sulfur atoms. In some embodiments, the materialmay exclude an organic material. The material may comprise a solid or aliquid. In some embodiments, the material may comprise a silicon-basedmaterial, for example, silicon based polymer or a resin. The materialmay comprise an organosilicon-based material. The material may comprisesilicon and hydrogen atoms. The material may comprise silicon and carbonatoms. In some embodiments, the material may exclude a silicon-basedmaterial. The solid material may comprise powder material. The powdermaterial may be coated by a coating (e.g., organic coating such as theorganic material (e.g., plastic coating)). The material may be devoid oforganic material. The liquid material may be compartmentalized intoreactors, vesicles, or droplets. The compartmentalized material may becompartmentalized in one or more layers. The material may be a compositematerial comprising a secondary material. The secondary material can bea reinforcing material (e.g., a material that forms a fiber). Thereinforcing material may comprise a carbon fiber, Kevlar®, Twaron®,ultra-high-molecular-weight polyethylene, or glass fiber. The materialcan comprise powder (e.g., granular material) or wires. The solidparticulate material may be powder. The material may exclude a polymerand/or a resin. The polymer may be a molecule having a repeatingmolecular unit. The polymer and/or resin may be an organic (e.g.,comprising of hydrogen and carbon). The polymer and/or resin may be anypolymer and/or resin disclosed herein. In some embodiments, the materialmay include a polymer.

In some embodiments, the material comprises a particulate material. Theparticulate material may comprise solid, or semi-solid (e.g., gel)particles. The solid particulate material comprises a powder. In someembodiments, the material comprises a powder material. The material maycomprise a solid material. The material may comprise one or moreparticles or clusters. The term “powder,” as used herein, generallyrefers to a solid having fine particles. Powders may be granularmaterials. The powder particles may comprise micro particles. The powderparticles may comprise nanoparticles. In some examples, a powdercomprising particles having an average FLS of at least about 5nanometers (nm), 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 100 nm, 200 nm, 300nm, 400 nm, 500 nm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, or100 μm. The particles comprising the powder may have an average FLS ofat most about 100 μm, 80 μm, 75 μm, 70 μm, 65 μm, 60 μm, 55 μm, 50 μm,45 μm, 40 μm, 35 μm, 30 μm, 25 μm, 20 μm, 15 μm, 10 μm, 5 μm, 1 μm, 500nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 40 nm, 30 nm, 20 nm, 10 nm,or 5 nm. In some cases, the powder may have an average FLS between anyof the values of the average particle FLS listed above (e.g., from about5 nm to about 100 μm, from about 1 μm to about 100 μm, from about 15 μmto about 45 μm, from about 5 μm to about 80 μm, from about 20 μm toabout 80 μm, or from about 500 nm to about 50 μm).

The powder can be composed of individual particles. The individualparticles can be spherical, oval, prismatic, cubic, or irregularlyshaped. The particles can have a FLS. The powder can be composed of ahomogenously shaped particle mixture such that all of the particles havesubstantially the same shape and FLS magnitude within at most 1%, 5%,8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, or 70%, distribution ofFLS. In some cases, the powder can be a heterogeneous mixture such thatthe particles have variable shape and/or FLS magnitude.

In some embodiments, at least parts of the layer of pre-transformedmaterial can be transformed to a transformed material as at least aportion of the 3D object. The transformed material may subsequently format least a fraction (also used herein “a portion,” or “a part”) of ahardened (e.g., solidified) 3D object. At times a layer of transformedor hardened material may comprise a cross section of a 3D object (e.g.,a horizontal cross section). At times, a layer of transformed and/orhardened material may comprise a deviation from a cross section of a 3Dmodel of a desired 3D object (e.g., an originally intended design to beproduced as a printed 3D object). The deviation may include vertical orhorizontal deviation with respect to the 3D model of the intended 3Dobject.

A pre-transformed material layer (or a portion thereof) can have athickness of at least about 1.0 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm.An un-transformed material layer (or a portion thereof) can have athickness of at most about 1000 μm, 900 μm, 800 μm, 700 μm, 60 μm, 500μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm, 200 μm, 150 μm, 100 μm, 75μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm. A pre-transformed materiallayer (or a portion thereof) may have any value in between theaforementioned values (e.g., from about 1000 μm to about 1 μm, 800 μm toabout 10 μm, 600 μm to about 20 μm, 300 μm to about 30 μm, or 1000 μm toabout 10 μm).

The material composition of at least one layer within the material bedmay differ from the material composition within at least one other layerin the material bed. The difference (e.g., variation) may comprisedifference in crystal and/or grain structure. The variation may comprisevariation in grain orientation, variation in material density, variationin the degree of compound segregation to grain boundaries, variation inthe degree of element segregation to grain boundaries, variation inmaterial phase, variation in metallurgical phase, variation in materialporosity, variation in crystal phase, and variation in crystalstructure. The microstructure of the printed object may comprise planarstructure, cellular structure, columnar dendritic structure, or equiaxeddendritic structure.

The pre-transformed materials of at least one layer in the material bedmay differ in the FLS of its particles (e.g., powder particles) from theFLS of the pre-transformed material within at least one other layer inthe material bed. A layer may comprise two or more material types at anycombination. For example, two or more elemental metals, two or moremetal alloys, two or more ceramics, two or more allotropes of elementalcarbon. For example, an elemental metal and a metal alloy, an elementalmetal and a ceramic, an elemental metal and an allotrope of elementalcarbon, a metal alloy and a ceramic, a metal alloy and an allotrope ofelemental carbon, a ceramic and an allotrope of elemental carbon. Allthe layers of pre-transformed material deposited during the 3D printingprocess may be of the same material composition. In some instances, ametal alloy is formed in situ during the process of transforming atleast a portion of the material bed. In some instances, a metal alloy isnot formed in situ during the process of transforming at least a portionof the material bed. In some instances, a metal alloy is formed prior tothe process of transforming at least a portion of the material bed. In amultiplicity (e.g., mixture) of pre-transformed materials, onepre-transformed material may be used as support (i.e., supportivepowder), as an insulator, as a cooling member (e.g., heat-sink), or asany combination thereof.

In some instances, adjacent components in the material bed (e.g., layersof hardened material) are separated from one another by one or moreintervening layers of pre-transformed material. In an example, a firstlayer is adjacent to a second layer when the first layer is in directcontact with the second layer. In another example, a first layer isadjacent to a second layer when the first layer is separated from thesecond layer by at least one layer (e.g., a third layer). Theintervening layer may be of any layer size disclosed herein.

The pre-transformed material (e.g., powder material) can be chosen suchthat the material type is the desired and/or otherwise predeterminedmaterial type for the 3D object. In some cases, a layer of the 3D objectcomprises a single type of material. In some examples, a layer of the 3Dobject may comprise a single elemental metal type, or a single metalalloy type. In some examples, a layer within the 3D object may compriseseveral types of material (e.g., an elemental metal and an alloy, analloy and a ceramic, an alloy and an allotrope of elemental carbon). Incertain embodiments each type of material comprises only a single memberof that type. For example: a single member of elemental metal (e.g.,iron), a single member of metal alloy (e.g., stainless steel), a singlemember of ceramic material (e.g., silicon carbide or tungsten carbide),or a single member (e.g., an allotrope) of elemental carbon (e.g.,graphite). In some cases, a layer of the 3D object comprises more thanone type of material. In some cases, a layer of the 3D object comprisesmore than one member of a material type.

The layer structure may comprise any material(s) used for 3D printingdescribed herein. Sometimes one part of the layer may comprise onematerial, and another part may comprise a second material different thanthe first material. A layer of the 3D object may be composed of acomposite material. The 3D object may be composed of a compositematerial. The 3D object may comprise a functionally graded material.

The elemental metal can be an alkali metal, an alkaline earth metal, atransition metal, a rare earth element metal, or another metal. Thealkali metal can be Lithium, Sodium, Potassium, Rubidium, Cesium, orFrancium. The alkali earth metal can be Beryllium, Magnesium, Calcium,Strontium, Barium, or Radium. The transition metal can be Scandium,Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper,Zinc, Yttrium, Zirconium, Platinum, Gold, Rutherfordium, Dubnium,Seaborgium, Bohrium, Hassium, Meitnerium, Ununbium, Niobium, Iridium,Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium,Hafnium, Tantalum, Tungsten, Rhenium, or Osmium. The transition metalcan be mercury. The rare earth metal can be a lanthanide, or anactinide. The lanthanide metal can be Lanthanum, Cerium, Praseodymium,Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium,Dysprosium, Holmium, Erbium, Thulium, Ytterbium, or Lutetium. Theactinide metal can be Actinium, Thorium, Protactinium, Uranium,Neptunium, Plutonium, Americium, Curium, Berkelium, Californium,Einsteinium, Fermium, Mendelevium, Nobelium, or Lawrencium. The othermetal can be Aluminum, Gallium, Indium, Tin, Thallium, Lead, or Bismuth.

The metal alloy can be an iron based alloy, nickel based alloy, cobaltbased allow, chrome based alloy, cobalt chrome based alloy, titaniumbased alloy, magnesium based alloy, copper based alloy, scandium alloy,or any combination thereof. The alloy may comprise an oxidation orcorrosion resistant alloy. The alloy may comprise a super alloy (e.g.,Inconel). The super alloy may comprise Inconel 600, 617, 625, 690, 718,or X-750. The metal (e.g., alloy or elemental) may comprise an alloyused for applications in industries comprising aerospace (e.g.,aerospace super alloys), jet engine, missile, automotive, marine,locomotive, satellite, defense, oil & gas, energy generation,semiconductor, fashion, construction, agriculture, printing, or medical.The metal (e.g., alloy or elemental) may comprise an alloy used forproducts comprising, devices, medical devices (human & veterinary),machinery, cell phones, semiconductor equipment, generators, engines,pistons, electronics (e.g., circuits), electronic equipment, agricultureequipment, motor, gear, transmission, communication equipment, computingequipment (e.g., laptop, cell phone, tablet, i-pad), air conditioning,generators, furniture, musical equipment, art, jewelry, cookingequipment, or sport gear. The metal (e.g., alloy or elemental) maycomprise an alloy used for products for human or veterinary applicationscomprising implants, or prosthetics. The metal alloy may comprise analloy used for applications in the fields comprising human or veterinarysurgery, implants (e.g., dental), or prosthetics.

The alloy may include a superalloy. The alloy may include ahigh-performance alloy. The alloy may include an alloy exhibiting atleast one of excellent mechanical strength, resistance to thermal creepdeformation, good surface stability, resistance to corrosion, andresistance to oxidation. The alloy may include a face-centered cubicaustenitic crystal structure. The alloy may comprise Hastelloy, Inconel,Waspaloy, Rene alloy (e.g., Rene-80, Rene-77, Rene-220, or Rene-41),Haynes alloy, Incoloy, MP98T, TMS alloy, MTEK (e.g., MTEK gradeMAR-M-247, MAR-M-509, MAR-M-R41, or MAR-M-X-45), or CMSX (e.g., CMSX-3,or CMSX-4). The alloy can be a single crystal alloy.

In some instances, the iron alloy comprises Elinvar, Fernico,Ferroalloys, Invar, Iron hydride, Kovar, Spiegeleisen, Staballoy(stainless steel), or Steel. In some instances, the metal alloy issteel. The Ferroalloy may comprise Ferroboron, Ferrocerium, Ferrochrome,Ferromagnesium, Ferromanganese, Ferromolybdenum, Ferronickel,Ferrophosphorus, Ferrosilicon, Ferrotitanium, Ferrouranium, orFerrovanadium. The iron alloy may include cast iron, or pig iron. Thesteel may include Bulat steel, Chromoly, Crucible steel, Damascus steel,Hadfield steel, High speed steel, HSLA steel, Maraging steel (M300),Reynolds 531, Silicon steel, Spring steel, Stainless steel, Tool steel,Weathering steel, or Wootz steel. The high-speed steel may includeMushet steel. The stainless steel may include AL-6XN, Alloy 20,celestrium, marine grade stainless, Martensitic stainless steel,surgical stainless steel, or Zeron 100. The tool steel may includeSilver steel. The steel may comprise stainless steel, Nickel steel,Nickel-chromium steel, Molybdenum steel, Chromium steel,Chromium-vanadium steel, Tungsten steel, Nickel-chromium-molybdenumsteel, or Silicon-manganese steel. The steel may be comprised of anySociety of Automotive Engineers (SAE) grade such as 440F, 410, 312, 430,440A, 440B, 440C, 304, 305, 304L, 304L, 301, 304LN, 301LN, 2304, 316,316L, 316LN, 317L, 2205, 409, 904L, 321, 254SMO, 316Ti, 321H, 17-4,15-5, 420, or 304H. The steel may comprise stainless steel of at leastone crystalline structure selected from the group consisting ofaustenitic, superaustenitic, ferritic, martensitic, duplex, andprecipitation-hardening martensitic. Duplex stainless steel may be leanduplex, standard duplex, super duplex, or hyper duplex. The stainlesssteel may comprise surgical grade stainless steel (e.g., austenitic 316,martensitic 420, or martensitic 440). The austenitic 316 stainless steelmay include 316L, or 316LVM. The steel may include 17-4 PrecipitationHardening steel (also known as type 630, a chromium-copper precipitationhardening stainless steel, 17-4PH steel).

The titanium-based alloys may include alpha alloys, near alpha alloys,alpha and beta alloys, or beta alloys. The titanium alloy may comprisegrade 1, 2, 2H, 3, 4, 5, 6, 7, 7H, 8, 9, 10, 11, 12, 13, 14, 15, 16,16H, 17, 18, 19, 20, 21, 2, 23, 24, 25, 26, 26H, 27, 28, 29, 30, 31, 32,33, 34, 35, 36, 37, 38, or higher. In some instances, the titanium basealloy includes Ti-6Al-4V or Ti-6Al-7Nb.

The Nickel alloy may include Alnico, Alumel, Chromel, Cupronickel,Ferronickel, German silver, Hastelloy, Inconel, Monel metal, Nichrome,Nickel-carbon, Nicrosil, Nisil, Nitinol, Hastelloy X, Cobalt-Chromium,or Magnetically “soft” alloys. The magnetically “soft” alloys maycomprise Mu-metal, Permalloy, Supermalloy, or Brass. The brass mayinclude Nickel hydride, Stainless or Coin silver. The cobalt alloy mayinclude Megallium, Stellite (e. g. Talonite), Ultimet, or Vitallium. Thechromium alloy may include chromium hydroxide, or Nichrome.

The aluminum alloy may include AA-8000, Al—Li (aluminum-lithium),Alnico, Duralumin, Hiduminium, Kryron Magnalium, Nambe,Scandium-aluminum, or Y alloy. The magnesium alloy may be Elektron,Magnox, or T—Mg—Al—Zn (Bergman phase) alloy.

The copper alloy may comprise Arsenical copper, Beryllium copper,Billon, Brass, Bronze, Constantan, Copper hydride, Copper-tungsten,Corinthian bronze, Cunife, Cupronickel, Cymbal alloys, Devarda's alloy,Electrum, Hepatizon, Heusler alloy, Manganin, Molybdochalkos, Nickelsilver, Nordic gold, Shakudo, or Tumbaga. The Brass may include Calaminebrass, Chinese silver, Dutch metal, Gilding metal, Muntz metal,Pinchbeck, Prince's metal, or Tombac. The Bronze may include Aluminumbronze, Arsenical bronze, Bell metal, Florentine bronze, Guanin,Gunmetal, Glucydur, Phosphor bronze, Ormolu, or Speculum metal.

In some examples the material (e.g., powder material) comprises amaterial wherein its constituents (e.g., atoms or molecules) readilylose their outer shell electrons, resulting in a free flowing cloud ofelectrons within their otherwise solid arrangement. In some examples thematerial is characterized in having high electrical conductivity, lowelectrical resistivity, high thermal conductivity, or high density(e.g., as measured at ambient temperature (e.g., R. T., or 20° C.)). Thehigh electrical conductivity can be at least about 1*10⁵ Siemens permeter (S/m), 5*10⁵ S/m, 1*10⁶ S/m, 5*10⁶ S/m, 1*10⁷ S/m, 5*10⁷ S/m, or1*10⁸ S/m. The symbol “*” designates the mathematical operation “times,”or “multiplied by.” The high electrical conductivity can be any valuebetween the aforementioned electrical conductivity values (e.g., fromabout 1*10⁵ S/m to about 1*10⁸ S/m). The low electrical resistivity maybe at most about 1*10⁻⁵ ohm times meter (Ω*m), 5*10⁻⁶ Ω*m, 1*10⁻⁶ Ω*m,5*10⁻⁷ Ω*m, 1*10⁻⁷ Ω*m, 5*10⁻⁸, or 1*10⁻⁸ Ω*m. The low electricalresistivity can be any value between the aforementioned electricalresistivity values (e.g., from about 1×10⁻⁵ Ω*m to about 1×10⁻⁸ Ω*m).The high thermal conductivity may be at least about 20 Watts per meterstimes degrees Kelvin (W/mK), 50 W/mK, 100 W/mK, 150 W/mK, 200 W/mK, 205W/mK, 300 W/mK, 350 W/mK, 400 W/mK, 450 W/mK, 500 W/mK, 550 W/mK, 600W/mK, 700 W/mK, 800 W/mK, 900 W/mK, or 1000 W/mK. The high thermalconductivity can be any value between the aforementioned thermalconductivity values (e.g., from about 20 W/mK to about 1000 W/mK). Thehigh density may be at least about 1.5 grams per cubic centimeter(g/cm³), 2 g/cm³, 3 g/cm³, 4 g/cm³, 5 g/cm³, 6 g/cm³, 7 g/cm³, 8 g/cm³,9 g/cm³, 10 g/cm³, 11 g/cm³, 12 g/cm³, 13 g/cm³, 14 g/cm³, 15 g/cm³, 16g/cm³, 17 g/cm³, 18 g/cm³, 19 g/cm³, 20 g/cm³, or 25 g/cm³. The highdensity can be any value between the aforementioned density values(e.g., from about 1 g/cm³ to about 25 g/cm³).

A metallic material (e.g., elemental metal or metal alloy) can comprisesmall amounts of non-metallic materials, such as, for example, oxygen,sulfur, or nitrogen. In some cases, the metallic material can comprisethe non-metallic material in a trace amount. A trace amount can be atmost about 100000 parts per million (ppm), 10000 ppm, 1000 ppm, 500 ppm,400 ppm, 200 ppm, 100 ppm, 50 ppm, 10 ppm, 5 ppm, or 1 ppm (on the basisof weight, w/w) of non-metallic material. A trace amount can comprise atleast about 10 ppt, 100 ppt, 1 ppb, 5 ppb, 10 ppb, 50 ppb, 100 ppb, 200ppb, 400 ppb, 500 ppb, 1000 ppb, 1 ppm, 10 ppm, 100 ppm, 500 ppm, 1000ppm, or 10000 ppm (on the basis of weight, w/w) of non-metallicmaterial. A trace amount can be any value between the afore-mentionedtrace amounts (e.g., from about 10 parts per trillion (ppt) to about100000 ppm, from about 1 ppb to about 100000 ppm, from about 1 ppm toabout 10000 ppm, or from about 1 ppb to about 1000 ppm).

The one or more layers within the 3D object may be (e.g., substantially)planar (e.g., flat). The planarity of the layer may be (e.g.,substantially) uniform. The height of the layer at a particular positionmay be compared to an average plane. The average plane may be defined bya least squares planar fit of the top-most part of the surface of thelayer of hardened material. The average plane may be a plane calculatedby averaging the material height at each point on the top surface of thelayer of hardened material. The deviation from any point at the surfaceof the planar layer of hardened material may be at most 20% 15%, 10%,5%, 3%, 1%, or 0.5% of the height (e.g., thickness) of the layer ofhardened material. The substantially planar one or more layers may havea large radius of curvature. FIG. 2 shows an example of a vertical crosssection of a 3D object 212 comprising planar layers (layer numbers 1-4)and non-planar layers (layer numbers 5-6) that have a radius ofcurvature. FIGS. 2, 216 and 217 are super-positions of curved layer on acircle 215 having a radius of curvature “r.” The one or more layers mayhave a radius of curvature equal to the radius of curvature of the layersurface. The radius of curvature of the layer surface (e.g., all thelayers of the 3D object) may have a value of at least about 0.1centimeter (cm), 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm,0.9 cm, 1 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80cm, 90 cm, 1 meter (m), 1.5 m, 2 m, 2.5 m, 3 m, 3.5 m, 4 m, 4.5 m, 5 m,10 m, 15 m, 20 m, 25 m, 30 m, 50 m, or 100 m. The radius of curvature ofthe layer surface (e.g., all the layers of the 3D object) may have anyvalue between any of the afore-mentioned values of the radius ofcurvature (e.g., from about 10 cm to about 90 m, from about 50 cm toabout 10 m, from about 5 cm to about 1 m, from about 50 cm to about 5 m,from about 5 cm to infinity, or from about 40 cm to about 50 m). A layerwith an infinite radius of curvature is a layer that is planar. In someexamples, the one or more layers may be included in a planar section ofthe 3D object, or may be a planar 3D object (e.g., a flat plane). Insome instances, part of at least one layer within the 3D object has theradius of curvature mentioned herein.

The 3D object may comprise a layering plane N of the layered structure(e.g., FIG. 8C, 805). The 3D object may comprise points X and Y, whichreside on the surface of the 3D object, wherein X is spaced apart from Yby the auxiliary feature spacing distance (e.g., as disclosed herein).FIG. 10 shows an example of points X and Y on the surface of a 3Dobject. In an example, a sphere of radius XY that is centered at X lacksone or more auxiliary supports or one or more auxiliary support marksthat are indicative of a presence or removal of the one or moreauxiliary support features. In some examples an acute angle formsbetween the straight line XY and the direction normal to N. The acuteangle between the straight line XY and the direction normal to thelayering plane may be of the value of the acute angle alpha (e.g., asdisclosed herein). When the angle between the straight line XY and thedirection of normal to N is greater than 90 degrees, one can considerthe complementary acute angle.

In some embodiments, the generated 3D object may be generated with theaccuracy of at least about 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85μm, 90 μm, 95 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, or 1500 μm ascompared to a 3D model of the 3D object (e.g., the desired 3D object).As compared to a 3D model of the 3D object, the generated 3D object maybe generated with the accuracy of any accuracy value between theaforementioned values (e.g., from about 5 μm to about 100 μm, from about15 μm to about 35 μm, from about 100 μm to about 1500 μm, from about 5μm to about 1500 μm, or from about 400 μm to about 600 μm).

In some embodiments, the hardened layer of transformed material deforms.The deformation may cause a height deviation from a uniformly planarlayer of hardened material. The height uniformity of the planar surfaceof the layer of hardened material may be at most about 100 μm, 90 μm,80, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, or 5 μm. The heightuniformity of the planar surface of the layer of hardened material maybe any value between the afore-mentioned height deviation values (e.g.,from about 100 μm to about 5 μm, from about 50 μm to about 5 μm, fromabout 30 μm to about 5 μm, or from about 20 μm to about 5 μm). Theheight uniformity may comprise high precision uniformity. The heightuniformity may be a deviation from a prescribed layer height, from amean layer height, or from an average layer height. The resolution ofthe 3D object may have any value of the height uniformity valuementioned herein. The resolution of the 3D object may be at least about100 dots per inch (dpi), 300 dpi, 600 dpi, 1200 dpi, 2400 dpi, 3600 dpi,or 4800 dpi. The resolution of the 3D object may be at most about 100dpi, 300 dpi, 600 dpi, 1200 dpi, 2400 dpi, 3600 dpi, or 4800 dip. Theresolution of the 3D object may be any value between the aforementionedvalues (e.g., from 100 dpi to 4800 dpi, from 300 dpi to 2400 dpi, orfrom 600 dpi to 4800 dpi). The height uniformity of a layer of hardenedmaterial may persist across a portion of the layer surface that has awidth or a length of at least about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or 10mm, have a height deviation of at least about 10 mm, 9 mm, 8 mm, 7 mm, 6mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 500 μm, 400 μm, 300 μm, 200 μm, 100μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10 μm.The height uniformity of a layer of hardened material may persist acrossa portion of the target surface that has a width or a length of or ofany value between the afore-mentioned width or length values (e.g., fromabout 10 mm to about 10 μm, from about 10 mm to about 100 μm, or fromabout 5 mm to about 500 μm).

At least one layer of the printed 3D objects may deviate from a planaruniformity of the layer of pre-transformed material (e.g., powder) in atleast one plane (e.g., horizontal plane) of at most about 20%, 10%, 5%,2%, 1% or 0.5%, as compared to the average or mean plane (e.g.,horizontal plane) created at the exposed surface of the material bed(e.g., top of a powder bed). The height deviation can be measured byusing one or more sensors (e.g., optical sensors).

Characteristics of the hardened material and/or any of its parts (e.g.,layer of hardened material) can be measured by any of the followingmeasurement methodologies. For example, the FLS values (e.g., width),height uniformity, auxiliary support space, an/d or radius of curvatureof the layer of the 3D object and any of its components (e.g., layer ofhardened material) may be measured by any of the following measuringmethodologies. The FLS of opening ports may be measured by one or moreof following measurement methodologies. The measurement methodologiesmay comprise a microscopy method (e.g., any microscopy method describedherein). The measurement methodologies may comprise a coordinatemeasuring machine (CMM), measuring projector, vision measuring system,and/or a gauge. The gauge can be a gauge distometer (e.g., caliber). Thegauge can be a go-no-go gauge. The measurement methodologies maycomprise a caliper (e.g., Vernier caliper), positive lens,interferometer, or laser (e.g., tracker). The measurement methodologiesmay comprise a contact or by a non-contact method. The measurementmethodologies may comprise one or more sensors (e.g., optical sensorsand/or metrological sensors). The measurement methodologies may comprisea metrological measurement device (e.g., using metrological sensor(s)).The measurements may comprise a motor encoder (e.g., rotary and/orlinear). The measurement methodologies may comprise using anelectromagnetic beam (e.g., visible or infra-red (IR)). The microscopymethod may comprise ultrasound or nuclear magnetic resonance. Themicroscopy method may comprise optical microscopy. The microscopy methodmay comprise electromagnetic, electron, or proximal probe microscopy.The electron microscopy may comprise scanning, tunneling, X-ray photo-,or Auger electron microscopy. The electromagnetic microscopy maycomprise confocal, stereoscope, or compound microscopy. The microscopymethod may comprise an inverted and/or non-inverted microscope. Theproximal probe microscopy may comprise atomic force, or scanningtunneling microscopy, or any other microscopy described herein. Themicroscopy measurements may comprise using an image analysis system. Themeasurements may be conducted at ambient temperatures (e.g., R.T.)

The microstructures (e.g., of melt pools) of the 3D object may bemeasured by a microscopy method (e.g., any microscopy method describedherein). The microstructures may be measured by a contact or by anon-contact method. The microstructures may be measured by using anelectromagnetic beam (e.g., visible or IR). The microstructuremeasurements may comprise evaluating the dendritic arm spacing and/orthe secondary dendritic arm spacing (e.g., using microscopy). Themicroscopy measurements may comprise using an image analysis system. Themeasurements may be conducted at ambient temperatures (e.g., R.T.).

Various distances relating to the chamber can be measured using any ofthe following measurement techniques. Various distances within thechamber can be measured using any of the following measurementtechniques. For example, the gap distance (e.g., from the cooling memberto the exposed surface of the material bed) may be measured using any ofthe following measurement techniques. The measurements techniques maycomprise interferometry and/or confocal chromatic measurements. Themeasurements techniques may comprise at least one motor encoder (rotary,linear). The measurement techniques may comprise one or more sensors(e.g., optical sensors and/or metrological sensors). The measurementtechniques may comprise at least one inductive sensor. The measurementtechniques may include an electromagnetic beam (e.g., visible or IR).The measurements may be conducted at ambient temperature (e.g., R.T.).

The 3D object can have various surface roughness profiles, which may besuitable for various applications. The surface roughness may be thedeviations in the direction of the normal vector of a real surface, fromits ideal form. The surface roughness may be measured as the arithmeticaverage of the roughness profile (hereinafter “Ra”). The formed objectcan have a Ra value of at most about 200 μm, 100 μm, 75 μm, 50 μm, 45μm, 40 μm, 35 μm, 30 μm, 25 μm, 20 μm, 15 μm, 10 μm, 7 μm, 5 μm, 3 μm, 1μm, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 40 nm, or 30 nm. The3D object can have a Ra value between any of the aforementioned Ravalues (e.g., from about 50 μm to about 1 μm, from about 100 μm to about4 μm, from about 30 μm to about 3 μm, from about 60 nm to about 1 μm, orfrom about 80 nm to about 0.5 μm). The Ra values may be measured by acontact or by a non-contact method. The Ra values may be measured by aroughness tester and/or by a microscopy method (e.g., any microscopymethod described herein). The measurements may be conducted at ambienttemperatures (e.g., R.T.). The roughness (e.g., as Ra values) may bemeasured by a contact or by a non-contact method. The roughnessmeasurement may comprise one or more sensors (e.g., optical sensors).The roughness measurement may comprise a metrological measurement device(e.g., using metrological sensor(s)). The roughness may be measuredusing an electromagnetic beam (e.g., visible or IR).

The 3D object may be composed of successive layers (e.g., successivecross sections) of solid material that originated from a transformedmaterial (e.g., fused, sintered, melted, bound or otherwise connectedpowder material), and optionally subsequently hardened (e.g., FIGS.8A-8C). The transformed material may be connected to a hardened (e.g.,solidified) material. The hardened material may reside within the samelayer, or in another layer (e.g., a previous layer). In some examples,the hardened material comprises disconnected parts of the 3D object,that are subsequently connected by newly transformed material (e.g., byfusing, sintering, melting, binding or otherwise connecting a powdermaterial).

A cross section (e.g., vertical cross section) of the generated (i.e.,formed) 3D object may reveal a microstructure or a grain structureindicative of a layered deposition (e.g., FIGS. 8A-8B). Without wishingto be bound to theory, the microstructure or grain structure may arisedue to the solidification of transformed powder material that is typicalto and/or indicative of the 3D printing method. For example, a crosssection may reveal a microstructure resembling ripples or waves that areindicative of solidified melt pools that may be formed during the 3Dprinting process (e.g., FIGS. 8A-8B). The repetitive layered structureof the solidified melt pools may reveal the orientation at which thepart was printed (e.g., FIGS. 8B-8C). The cross section may reveal asubstantially repetitive microstructure or grain structure. Themicrostructure or grain structure may comprise (e.g., substantiallyrepetitive) variations in material composition, grain orientation,material density, degree of compound segregation or of elementsegregation to grain boundaries, material phase, metallurgical phase,crystal phase, crystal structure, material porosity, or any combinationthereof. The microstructure or grain structure may comprisesubstantially repetitive solidification of layered melt pools. The(e.g., substantially repetitive) microstructure may have an averagelayer width of at least about 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm,40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm. The (e.g., substantiallyrepetitive) microstructure may have an average layer width of at mostabout 500 μm, 450 μm, 400 μm, 350 μm, 300 μm, 250 μm, 200 μm, 150 μm,100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, or 10μm. The (e.g., substantially repetitive) microstructure may have anaverage layer size of any value between the aforementioned values oflayer widths (e.g., from about 0.5 μm to about 500 μm, from about 15 μmto about 50 μm, from about 5 μm to about 150 μm, from about 20 μm toabout 100 μm, or from about 10 μm to about 80 μm).

In some examples, the pre-transformed material within the material bed(e.g., powder bed) can provide support to the 3D object (e.g., duringits formation). For example, the supportive pre-transformed material maybe of the same type of pre-transformed material from which the 3D objectis generated, of a different type, or any combination thereof. In someinstances, a low flowability pre-transformed material (e.g., powder) canbe capable of supporting a 3D object better than a high flowabilitypre-transformed material. A low flowability pre-transformed material canbe achieved inter alia with a particulate material composed ofrelatively small particles, with particles of non-uniform size, and/orwith particles that attract each other. The pre-transformed material maybe of low, medium, or high flowability. In some examples, thepre-transformed material in the material bed may is flowable during the3D printing. The particulate material may have compressibility of atleast about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% in response to anapplied force of 15 kilo Pascals (kPa). The particulate material mayhave a compressibility of at most about 9%, 8%, 7%, 6%, 5%, 4.5%, 4.0%,3.5%, 3.0%, 2.5%, 2.0%, 1.5%, 1.0%, or 0.5% in response to an appliedforce of 15 kilo Pascals (kPa). The particulate material may have basicflow energy of at least about 100 milli-Joule (mJ), 200 mJ, 300 mJ, 400mJ, 450 mJ, 500 mJ, 550 mJ, 600 mJ, 650 mJ, 700 mJ, 750 mJ, 800 mJ, or900 mJ. The particulate material may have basic flow energy of at mostabout 200 mJ, 300 mJ, 400 mJ, 450 mJ, 500 mJ, 550 mJ, 600 mJ, 650 mJ,700 mJ, 750 mJ, 800 mJ, 900 mJ, or 1000 mJ. The particulate material mayhave basic flow energy in between the above listed values of basic flowenergy (e.g., from about 100 mj to about 1000 mJ, from about 100 mj toabout 600 mJ, or from about 500 mj to about 1000 mJ). The particulatematerial may have a specific energy of at least about 1.0 milli-Jouleper gram (mJ/g), 1.5 mJ/g, 2.0 mJ/g, 2.5 mJ/g, 3.0 mJ/g, 3.5 mJ/g, 4.0mJ/g, 4.5 mJ/g, or 5.0 mJ/g. The powder may have a specific energy of atmost 5.0 mJ/g, 4.5 mJ/g, 4.0 mJ/g, 3.5 mJ/g, 3.0 mJ/g, 2.5 mJ/g, 2.0mJ/g, 1.5 mJ/g, or 1.0 mJ/g. The particulate material may have aspecific energy in between any of the above values of specific energy(e.g., from about 1.0 mFg to about 5.0 mJ/g, from about 3.0 mJ/g toabout 5 mJ/g, or from about 1.0 mJ/g to about 3.5 mJ/g).

The 3D object can have one or more auxiliary features. The auxiliaryfeature(s) can be supported by the material (e.g., powder) bed at leastduring the 3D printing. The term “auxiliary features,” as used herein,generally refers to features that are part of a printed 3D object, butare not part of the desired, intended, designed, ordered, modeled, orfinal 3D object. Auxiliary features (e.g., auxiliary supports) mayprovide structural support during and/or subsequent to the formation ofthe 3D object. Auxiliary features may enable the removal or energy fromthe 3D object that is being formed. Auxiliary features may enablereduction of deformations of at least a portion of a generated 3Dobject, which deformations would otherwise manifest themselves in theprinted 3D object. Examples of auxiliary features comprise heat fins,wires, anchors, handles, supports, pillars, columns, frame, footing,scaffold, flange, projection, protrusion, mold (a.k.a. mould), buildplatform, or other stabilization features. In some instances, theauxiliary support is a scaffold that encloses the 3D object or partthereof. The scaffold may comprise lightly sintered or lightly fusedpowder material. The 3D object can have auxiliary features that can besupported by the material bed (e.g., powder bed) and not touch thebuilding platform (e.g., the base, substrate, container accommodatingthe material bed, or the bottom of the enclosure). The 3D part (3Dobject) in a complete or partially formed state can be completelysupported by the material bed (e.g., without touching at least one ofthe platform, container accommodating the material bed, and enclosure).The 3D object in a complete or partially formed state can be completelysupported by the material bed (e.g., without touching anything exceptthe material bed). The material bed may comprise a flowable (e.g., notfixed) material during the 3D printing process. The 3D object in acomplete or partially formed state can be suspended in the material bedwithout resting on any additional support structures. In some cases, the3D object in a complete or partially formed state can freely float(e.g., anchorless) in the material bed.

The printed 3D object may be 3D printed without the use of auxiliaryfeatures, may be printed using a reduced number of auxiliary features,or printed using spaced apart auxiliary features. In some embodiments,the printed 3D object may be devoid of one or more auxiliary supportfeatures (e.g., during the 3D printing) or auxiliary support featuremarks that are indicative of a presence or removal of the auxiliarysupport features. The 3D object may be devoid of one or more auxiliarysupport features (e.g., during the 3D printing) and of one or more marksof an auxiliary feature (including a base structure) that was removed(e.g., subsequent to, or contemporaneous with, the generation of the 3Dobject). The printed 3D object may comprise a single auxiliary supportmark. The single auxiliary feature (e.g., auxiliary support or auxiliarystructure) may be a platform or a mold. The auxiliary support may beadhered to the platform and/or mold. The 3D object may comprise marksbelonging to one or more auxiliary structures. FIG. 17 shows an exampleof a segment 1700 of a 3D object comprising an auxiliary support feature1701 that has a point of discontinuity (e.g., trimming) 1702, whichauxiliary support feature 1701 imparts a geometric deformation in the 3Dobject (e.g., 1703). In some embodiments, the 3D object comprises two ormore marks belonging to auxiliary features. The 3D object may be devoidof marks pertaining to an auxiliary support(s). The mark may comprisevariation in grain orientation, variation in layering orientation,layering thickness, material density, the degree of compound segregationto grain boundaries, material porosity, the degree of elementsegregation to grain boundaries, material phase, metallurgical phase,crystal phase, or crystal structure; wherein the variation may not havebeen created by the geometry of the 3D object alone, and may thus beindicative of a prior existing auxiliary support that was removed. Thevariation may be forced upon the generated 3D object by the geometry ofthe support (e.g., FIG. 17, 1703). In some instances, the 3D structureof the printed object may be forced by the auxiliary support (e.g., by amold). For example, a mark may be a point of discontinuity (e.g., a trimor cut. E.g., FIG. 17, 1702) that is not explained by the geometry ofthe 3D object that is formed without any auxiliary supports. A mark maybe a surface feature that cannot be explained by the geometry of a 3Dobject that is formed without any auxiliary supports (e.g., a mold). Thetwo or more auxiliary features (or auxiliary support feature marks) maybe spaced apart by a spacing distance of at least about 1.5 millimeters(mm), 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm,11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm,16 mm, 20 mm, 20.5 mm, 21 mm, 25 mm, 30 mm, 30.5 mm, 31 mm, 35 mm, 40mm, 40.5 mm, 41 mm, 45 mm, 50 mm, 80 mm, 100 mm, 200 mm 300 mm, or 500mm. The two or more auxiliary support features or auxiliary supportfeature marks may be spaced apart by a spacing distance of any valuebetween the aforementioned auxiliary support space values (e.g., from1.5 mm to 500 mm, from 2 mm to 100 mm, from 15 mm to 50 mm, or from 45mm to 200 mm). Collectively referred to herein as the “auxiliary featurespacing distance.”

he 3D object may comprise a layered structure that is indicative of 3Dprinting process, which includes one, two, or more auxiliary supportmarks. The supports or support marks can be on the surface of the 3Dobject. The auxiliary supports or support marks can be on an external,on an internal surface (e.g., a cavity within the 3D object), or both.The layered structure can have a layering plane (e.g., FIG. 8C, 805). Inone example, two auxiliary support features or auxiliary support featuremarks present in the 3D object may be spaced apart by the auxiliaryfeature spacing distance. The acute (i.e., sharp) angle alpha betweenthe straight line connecting the two auxiliary supports or auxiliarysupport marks and the direction of normal to the layering plane may beat least about 45 degrees(°), 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°.The acute angle alpha between the straight line connecting the twoauxiliary supports or auxiliary support marks and the direction ofnormal to the layering plane may be at most about 90°, 85°, 80°, 75°,70°, 65°, 60°, 55°, 50°, or 45°. The acute angle alpha between thestraight line connecting the two auxiliary supports or auxiliary supportmarks and the direction of normal to the layering plane may be any anglerange between the aforementioned angles (e.g., from about 45 degrees(°),to about 90°, from about 60° to about 90°, from about 75° to about 90°,from about 80° to about 90°, from about 85° to about 90°). The acuteangle alpha between the straight line connecting the two auxiliarysupports or auxiliary support marks and the direction normal to thelayering plane may from about 87° to about 90°. An example of layeringplanes can be seen in FIG. 2 showing a vertical cross section of a 3Dobject 211 that comprises layer numbers 1 to 6, each of which are (e.g.,substantially) planar. In the schematic example in FIG. 2, the layeringplane of the layers can be the layer of hardened material. For example,layer 1 could correspond to both the layer of hardened material and thelayering plane of layer 1. When the layer is not planar (e.g., FIG. 2,layer 5 of 3D object 212), the layering plane may be the average (ormean) plane of the layer of hardened material. The two auxiliarysupports or auxiliary support feature marks can be on the same surface.The same surface can be an external surface or an internal surface ofthe 3D object (e.g., a surface of a cavity within the 3D object). Whenthe angle between the shortest straight line connecting the twoauxiliary supports or auxiliary support marks and the direction ofnormal to the layering plane is greater than 90° (degrees), one canconsider the complementary acute angle. In some embodiments, any twoauxiliary supports or auxiliary support marks are spaced apart by theauxiliary feature spacing distance. FIG. 8C shows an example of a 3Dobject comprising an exposed surface 801 that was comprises layers ofhardened material (e.g., having layering plane 805) that are (e.g.,substantially) parallel to the platform 803. FIG. 8C shows an example ofa 3D object comprising an exposed surface 802 that comprises layers ofhardened material (e.g., having layering plane 806) that aresubstantially parallel to the platform 803 resulting in a tilted 3Dobject (e.g., box). The 3D object that was formed as a tilted 3D object(comprising 802 and 806), is shown after it printing as lying flat on asurface 809 having an exposed surface 804 and layers of hardenedmaterial (e.g., having layering plane 807) having a normal 808 to thelayering plane (e.g., 807) that forms acute angle alpha with the exposedsurface 804 of the 3D object (or with the platform 809). FIGS. 8A and 8Bshow 3D objects comprising layers of solidified melt pools that arearranged in layers having layering planes (e.g., 820). FIG. 9 shows avertical cross section in a coordinate system. Line 904 represents avertical cross section of the top surface of a material bed and/or aplatform. Line 903 represents a normal to the average layering plane.Line 902 represent the normal to the top surface of the material bedand/or platform. Line 901 represents the direction of the gravitationalfield.

The one or more auxiliary features (which may include a base support)can be used to hold or restrain the 3D object during its formation. Insome cases, auxiliary features are used to anchor or hold a 3D object ora portion of a 3D object in a material bed. The one or more auxiliaryfeatures can be specific to a 3D part and can increase the time neededto form it. The one or more auxiliary features can be removed subsequentto the 3D printing, and prior to use or distribution of the 3D object.The FLS (e.g., longest dimension) of a cross-section of an auxiliaryfeature can be at most about 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm, 1 μm, 3 μm, 10 μm, 20μm, 30 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 700 μm, 1 mm, 3 mm, 5mm, 10 mm, 20 mm, 30 mm, 50 mm, 100 mm, or 300 mm. The FLS (e.g.,longest dimension) of a cross-section of an auxiliary feature can be atleast about 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700nm, 800 nm, 900 nm, or 1000 nm, 1 μm, 3 μm, 10 μm, 20 μm, 30 μm, 100 μm,200 μm, 300 μm, 400 μm, 500 μm, 700 μm, 1 mm, 3 mm, 5 mm, 10 mm, 20 mm,30 mm, 50 mm, 100 mm, or 300 mm. The longest dimension of across-section of an auxiliary feature can be any value between theabove-mentioned values (e.g., from about 50 nm to about 300 mm, fromabout 5 μm to about 10 mm, from about 50 nm to about 10 mm, or fromabout 5 mm to about 300 mm).

Eliminating the need for auxiliary features can decrease the time and/orcost associated with generating the 3D part. In some examples, the 3Dobject is formed with auxiliary support features. In some examples, the3D object is formed with contact to the container accommodating thematerial bed (e.g., side(s) and/or bottom of the container). In someexamples, the diminished number of auxiliary supports or lack of one ormore auxiliary support, provides a 3D printing process that requires asmaller amount of material, produces a smaller amount of material waste,and/or requires smaller energy as compared to commercially available 3Dprinting processes. The smaller amount can be smaller by at least about1.1, 1.3, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The smaller amount may besmaller by any value between the aforesaid values (e.g., from about 1.1to about 10, or from about 1.5 to about 5).

At least a portion of the 3D object can sink in the material bed. Atleast a portion of the 3D object can be surrounded by pre-transformedmaterial within the material bed (e.g., submerged). At least a portionof the 3D object can rest in the pre-transformed material withoutsubstantial sinking (e.g., vertical movement). Lack of substantialsinking can amount to a sinking (e.g., vertical movement) of at mostabout 40%, 20%, 10%, 5%, or 1% layer thickness. Lack of substantialsinking can amount to at most about 100 μm, 30 μm, 10 μm, 3 μm, or 1 μm.At least a portion of the 3D object can rest in the pre-transformedmaterial without substantial movement (e.g., horizontal movement,movement at an angle). Lack of substantial movement can amount to atmost 100 μm, 30 μm, 10 μm, 3 μm, or 1 μm. The 3D object can rest on thesubstrate when the 3D object is sunk or submerged in the material bed.

At least a fraction of the components in the system can be enclosed inthe chamber. At least a fraction of the chamber can comprise a gas tocreate a gaseous environment (i.e., an atmosphere). The gas can comprisean inert gas. The gas can be a non-reactive gas (e.g., an inert gas).The gaseous environment can comprise argon, nitrogen, helium, neon,krypton, xenon, hydrogen, carbon monoxide, or carbon dioxide. The 3Dprinting system, it apparatuses, and features can be any of thosedisclosed in Provisional Patent Application Ser. No. 62/396,584, thatwas filed on Sep. 19, 2016, titled “APPARATUSES, SYSTEMS AND METHODS FORTHREE-DIMENSIONAL PRINTING,” which is incorporated herein by referencein its entirety. The features can include, for example, the pressure inthe enclosure (e.g., chamber), or its gaseous layers. The apparatusescan comprise the controller, layer dispensing mechanism (and itscomponents), sensor, motor, valve, or pump. The components of the layerdispensing mechanism can comprise the material dispensing mechanism,leveling mechanism, or material removal mechanism. In some cases, thepressure in the chamber is standard atmospheric pressure. In some cases,the pressure in the chamber can be ambient pressure (e.g., neutralpressure). In some examples, the chamber can be under vacuum pressure.In some examples, the chamber can be under a positive pressure.

A thermal control unit (e.g., a cooling member such as a heat-sink (or acooling plate), a heating plate, or a thermostat) can be provided insideof the region where the 3D object is formed or adjacent to (e.g., above)the region where the 3D object is formed. Additionally, oralternatively, the thermal control unit can be provided outside of theregion where the 3D object is formed (e.g., at a predetermineddistance). In some cases, the thermal control unit can form at least onesection of a boundary region where the 3D object is formed (e.g., thecontainer accommodating the powder bed).

In another aspect, a system for forming a 3D object comprises: amaterial bed disposed adjacent to a platform comprising a firststructure having a bottom surface with a first curvature that isnegative, which structure comprises a hardened material; an energysource generating an energy beam that transforms at least a portion ofthe material bed into a transformed material; and at least onecontroller operatively coupled to the material bed and to the energybeam and is programmed to direct the energy beam (e.g., along a path) totransform at least a portion of the material bed into a transformedmaterial that couples to the top of the first structure to form a secondstructure, wherein a bottom of the second structure has a secondcurvature that is greater than the first curvature, wherein the firstcurvature is negative when a volume bound from the bottom surface to theplatform is a convex object, which bottom surface is disposed above theplatform, wherein bottom faces the platform, wherein top faces away fromthe platform. The transformed material may be part of the 3D object. Thetransformed material may be a hard material (e.g., in the case ofphoto-polymerization). The transformed material may subsequently hardeninto a hardened material as part of the 3D object (e.g., in the case ofmetal powder being molten and subsequently solidified). The controllermay comprise a plurality of controllers.

In another aspect, a system for forming a 3D object comprises: amaterial dispensing mechanism (e.g., material dispenser) that dispensesa pre-transformed material to form a material bed comprising a firstlayer of hardened material, (e.g., which material bed is disposedadjacent to (e.g., above) a platform); an energy source generating anenergy beam that transforms at least a portion of the material bed intoa transformed material; and at least one controller operatively coupledto the material dispensing mechanism and to the energy beam and isprogrammed to: (i) direct the material dispenser to dispense a layer ofpre-transformed material above the first layer of hardened material;(ii) direct the energy beam (e.g., along a path) to generate a secondlayer of hardened material from at least a portion of the layer ofpre-transformed material, wherein the first layer of hardened materialis separated from the second layer of hardened material by a gap,wherein the first layer of hardened material and the second layer ofhardened material form at least a portion of the 3D object. The gap maycomprise a material that is less dense than either the first layer ofhardened material and the second layer of hardened material. Above maybe relative to a direction away from the platform and/or opposite to thegravitational force. An exposed surface (e.g., top surface) of thedisposed layer of pre-transformed material may be substantially leveled.The at least one controller can be a first controller that isoperatively coupled to the material dispensing mechanism, and a secondcontroller that is operatively coupled to the energy beam. The first andsecond controllers can be different controllers. A third controller canbe operatively coupled to the energy source. The third controller can bedifferent than at least the first or second controller. The thirdcontroller can be the same controller as at least the first or secondcontroller.

In another aspect, a system for forming a 3D object comprises: amaterial dispensing mechanism that dispenses a pre-transformed materialto form a material bed that comprises a hardened material; an energysource generating an energy beam that transforms at least a portion ofthe material bed into a transformed material; a cooling member; and atleast one controller operatively connected to the material dispenser,energy beam, and cooling member and is programmed to: (i) direct thematerial dispenser to dispense a layer of pre-transformed materialadjacent to (e.g., above) the hardened material; (ii) direct the energybeam (e.g., along a path) to transform (e.g., melt) a portion of thelayer of pre-transformed material to form a transformed (e.g., molten)portion; (iii) direct the cooling member to harden (e.g., solidify) theexposed surface of the transformed portion while keeping the interior ofthe transformed portion in the transformed state; and (iv) direct thecooling member to harden the transformed portion to form at least aportion of the 3D object. The at least one controller can be a pluralityof controllers, wherein at least two of the operations (i) to (iv) arecontrolled by different controllers. The at least one controller can bea plurality of controllers, wherein at least two of the operations (i)to (iv) are controlled by the same controller.

In another aspect, a system for forming a 3D object comprises: amaterial dispensing mechanism that dispenses a pre-transformed materialto form a material bed, which material bed comprises a first hardenedmaterial; an energy source generating an energy beam that transforms atleast a portion of the pre-transformed material; a cooling member; andat least one controller operatively coupled to the material dispenser,the energy beam, and the cooling member, and is programmed to: (i)direct the material dispenser to dispose a layer of pre-transformedmaterial adjacent to (e.g., above) the first hardened material; (ii)direct the energy beam (e.g., along a path) to transform a portion ofthe layer of pre-transformed material and a portion of the firsthardened material to form a transformed (e.g., molten) portion and aremainder of the first hardened material; and (iii) optionally directthe cooling member to harden the transformed portion to form a secondhardened material and plastically deform a region comprising (1) aportion of the second hardened material, and (2) a portion of theremainder of the first hardened material that is bordering the secondhardened material, wherein the region comprises an exposed surface andan interior. In some examples, the exposed surface ceases to plasticallydeform before the interior ceases to plastically deform. In someexamples, the exposed surface ceases to plastically deform when theinterior ceases to plastically deform. In some examples, the exposedsurface ceases to plastically deform after the interior ceases toplastically deform. The cooling member may be a heat-sink. The coolingmember may be passive or active (e.g., comprise a moving coolant).

In another aspect, a system for forming a 3D object comprises: amaterial bed comprising pre-transformed material; an energy sourcegenerating an energy beam that transforms at least a portion of thematerial bed; and at least one controller that is operatively coupled tothe material bed and to the energy beam, and is programmed to direct theenergy beam (e.g., along a path) to transform at least a portion of amaterial bed and (directly or subsequently) form the 3D objectcomprising one or more layer portions having successive melt pools of ahardened (e.g., solidified) material, wherein the 3D object comprises asurface, and interior, and a grain structure. The grain structure closerto the surface may be indicative of a greater (e.g., faster)solidification rate than the grain structure in the interior. The grainstructure may be a microstructure. The grain structure may comprise ametallurgical and/or crystal structure.

In another aspect, a system for forming a 3D object comprises: amaterial bed comprising pre-transformed material; an energy sourcegenerating an energy beam that transforms at least a portion of thematerial bed; and at least one controller that is operatively coupled tothe material bed and to the energy beam, and is programmed to direct theenergy beam (e.g., along a path) to transform at least a portion of amaterial bed and form the 3D object (or a portion thereof) comprisingone or more layer portions having successive solidified melt pools of amaterial type, wherein the 3D object comprises a surface, an interior,and material microstructures (e.g., crystals. E.g., dendrites or cells).The material microstructures closer to the surface may be indicative ofa greater, lower, or substantially equal solidification rate than thematerial microstructures in the interior. For example, the materialmicrostructures closer to the surface may be indicative of a greatersolidification rate than the (e.g., respective) material microstructuresin the interior.

In another aspect, a system for forming a 3D object comprises: amaterial bed disposed adjacent to (e.g., above) a platform, whichmaterial bed comprising a first hardened material that comprises abottom surface facing towards the platform; a first energy sourcegenerating a first (e.g., radiation of) heat energy that heats (e.g.,but not transforms, such as melts) at least a portion of the firsthardened material; a second energy source that generates a second energybeam that melts a portion of the heated portion to form a moltenportion; an optional cooling member; and at least one controlleroperatively coupled to the material bed, the first heating energy, thesecond energy beam, and the optional cooling member, and is programmedto: (i) direct the first heat energy to heat at least a portion of thefirst hardened material to form a heated (e.g., but not transformed)portion; (ii) direct the second energy beam to transform (e.g., melt) atleast a portion of the heated portion to form a transformed (e.g.,molten) portion; and (iii) direct the cooling member to cool thetransformed portion to form a second hardened material that comprises abottom surface facing towards the platform. The bottom surface of thefirst hardened material may have a first curvature that is of a highervalue than a second curvature of the bottom surface of the secondhardened material. The bottom surface may have a negative curvature whena volume bound from the bottom surface to the platform is a convexobject, which bottom surface is disposed above the platform. Thematerial forming the 3D object (e.g., the first hardened material) maysubstantially exclude a resin and/or a polymer. The polymer may compriserepeating molecular units. The polymer and/or resin may be organic(e.g., comprise both hydrogen and carbon atoms). The first energy sourceand the second energy source may be the same energy source. The firstenergy source and the second energy source may be different energysources. The first heat energy may not transform the hardened material(e.g., only heat but not transform). The first heat energy may comprisea first energy beam. The first energy beam and the second energy beammay be the same energy beam. The first energy beam and the second energybeam may be different energy beams. The first heat energy may be aradiative heat source. The at least one controller can be a plurality ofcontrollers, wherein at least two of the operations (i) to (iii) arecontrolled by different controllers (e.g., different controllers). Theat least one controller can be a plurality of controllers, wherein atleast two of the operations (i) to (iii) are controlled by the samecontroller.

In another aspect, a system for forming a 3D object comprises: an energysource generating an energy beam that transforms at least a portion of amaterial bed into a transformed material, which material bed comprisespre-transformed material and is disposed in an enclosure; a firstcooling member that (i) cools the material bed, (ii) is translatable,and (iii) is disposed within the enclosure; a second cooling member thatcools the first cooling member, which second cooling member is notdisposed in the enclosure; and at least one controller that isoperatively coupled to the energy source, the first cooling member, andthe second cooling member, and is programmed to: (i) direct the energybeam (e.g., along a path) to transform at least a portion of thematerial bed into a transformed material; (ii) direct the first coolingmember to cool the material bed; and (iii) direct the second coolingmember to cool the first cooling member. The second cooling member maybe disposed outside of the enclosure. The second cooling member may bepart of a coating of the enclosure. The coating may be a wall or a rim.The first cooling member may be disposed adjacent to (e.g., above) thematerial bed. Adjacent may be above, below, or to the side. In someembodiments, adjacent may be above. Above may be in the directionopposite to the building platform. The at least one controller can be aplurality of controllers, wherein at least two of the operations (i) to(iii) are controlled by different controllers. The at least onecontroller can be a plurality of controller, wherein at least two of theoperations (i) to (iii) are controlled by the same controller.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is operatively coupled to an energy beam andis programmed to direct the energy beam (e.g., along a path) totransform at least a portion of a material bed into a transformedmaterial that couples to (e.g., attaches, merges, and/or contacts) a topof a first structure to form a second structure. The first structure mayhave a bottom surface having a first curvature that is negative and isdisposed in the material bed. In some embodiments, a bottom of thesecond structure has a second curvature that is greater than the firstcurvature. In some embodiments, a bottom of the second structure has asecond curvature that is smaller, substantially equal, or greater thanthe first curvature. The first curvature may be negative when a volumebound from the bottom surface to the platform is a convex object. Thebottom surface may be disposed above the platform. The bottom may facethe platform. The top may face away from the platform. The transformedmaterial may harden into a hardened material as part of the 3D object.The transformed material may form at least a portion of the 3D object.

The at least one controller may be operatively coupled to a levelingmember and is programmed to direct the leveling member to level theexposed surface of the material bed. The at least one controller may beoperatively coupled to a material removal member and is programmed todirect the material removal member to remove material from the materialbed. The removal of the material (e.g., pre-transformed material) fromthe material bed may result in a substantially planar (e.g., flat)exposed surface of the material bed. The removal may exclude contactingthe exposed surface of the material bed. The at least one controller cancomprise a plurality of controllers, wherein at least two of theleveling member, material removal member, and energy beam are controlledby different controllers. The at least one controller can comprise aplurality of controllers, wherein at least two of leveling member,material removal member, and energy beam are controlled by the samecontroller. In some examples, the material removal member comprises amaterial entrance opening and/or a material reservoir where the removedmaterial is collected. In some examples, the leveling member comprises ablade, roller, or reservoir where removed material is collected.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct a material dispensingmechanism to dispose an upper layer of pre-transformed material above afirst layer of hardened material disposed in a material bed thatcomprises the pre-transformed material, which material bed is disposedadjacent to a platform; and direct an energy beam (e.g., along a path)to generate a layer of hardened material from at least a portion of theupper layer of pre-transformed material, wherein the first layer ofhardened material is separated from the second layer of hardenedmaterial by a gap. The gap may comprise a material that is less densethan either the first layer of hardened material and/or the second layerof hardened material. For example, the gap may comprise pre-transformedmaterial, or sintered material (e.g., that is porous). The at least onecontroller may be operatively coupled to the material dispenser and/orto the energy beam. Above may be relative to a direction away from theplatform and/or a direction opposite to the gravitational field. The atleast one controller can comprise a first controller that is operativelycoupled to the material dispensing mechanism, and a second controllerthat is operatively coupled to the energy beam. The first and secondcontrollers can be different controllers. A third controller can beoperatively coupled to the energy source. The third controller can bedifferent than at least the first or second controller. The thirdcontroller can be the same controller as at least the first or secondcontroller.

In some examples, the material dispensing mechanism is integrated in alayer dispensing mechanism. The layer dispensing mechanism may comprisea material dispensing mechanism, a leveling mechanism, or a materialremoval mechanism. The at least one controller may be operativelycoupled to a leveling member and may be programmed to direct theleveling member to level the exposed surface of the material bed. The atleast one controller may be operatively coupled to a material removalmember and may be programmed to direct the material removal member toremove material from the material bed. The removal of the material fromthe material bed may result in a substantially planar (e.g., flat)exposed surface of the material bed. The removal may exclude contactingthe exposed surface of the material bed (e.g., by using electrostaticforce, magnetic force, and/or gas flow. The gas flow may comprisenegative pressure). The at least one controller can comprise a pluralityof controllers, wherein at least two of the mechanisms and the energybeam are controlled by different controllers. The at least onecontroller can comprise a plurality of controllers, wherein at least twoof the mechanisms and the energy beam are controlled by the samecontroller. The material dispensing mechanism may comprise an external3D surface (e.g., planar surface) that is slanted, an exit openingthrough which pre-transformed material exits an internal reservoir ofthe material dispensing mechanism, an entrance opening through whichpre-transformed material enters the internal reservoir of the materialdispensing mechanism, or an internal reservoir in which thepre-transformed material resides within the material dispensingmechanism. The material removal mechanism may comprise an exit openingthrough which removed material exits an internal reservoir of thematerial dispensing mechanism, an entrance opening through which removedmaterial enters the internal reservoir of the material dispensingmechanism, or an internal reservoir in which the removed materialresides within the material removal mechanism. The removed material maycomprise pre-transformed mater. The removed material may be removed fromthe material bed (e.g., during the 3D printing process). The levelingmechanism comprises a blade or a roller.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct a material dispensingmechanism to dispose a layer of pre-transformed material on a hardenedmaterial disposed in a material bed, which at least one controller isoperatively coupled to the material dispensing mechanism; direct anenergy beam (e.g., along a path) to melt a portion of the layer ofpre-transformed material to form a transformed (e.g., molten) portion,which at least one controller is operatively coupled to the energy beam;optionally direct a cooling member to harden the exposed surface of thetransformed portion while keeping the interior of the transformedportion in a transformed state (e.g., molten), which cooling member isoperatively coupled to the at least one controller; and direct thecooling member to harden the transformed portion to form at least aportion of the 3D object.). The at least one controller can comprise aplurality of controllers, wherein at least two of the materialdispensing mechanism, optional cooling member and the energy beam arecontrolled by different controllers. The at least one controller cancomprise a plurality of controller, wherein at least two of the materialdispensing mechanism, optional cooling member and the energy beam arecontrolled by the same controller.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to: direct a layer dispensingmechanism to dispense a layer of pre-transformed material on a hardenedmaterial that is disposed in the material bed, wherein the at least onecontroller is operatively coupled to the layer dispensing mechanism;direct an energy beam (e.g., along a path) to transform (e.g., melt) aportion of the layer of pre-transformed material and a portion of thefirst hardened material to form a transformed (e.g., molten) portion anda remainder of the first hardened material, wherein the at least onecontroller is operatively coupled to the energy beam; and direct anoptional cooling member to harden (e.g., solidify) the transformedportion to form a second hardened material and plastically deform aregion comprising (i) a portion of the second hardened material, and/or(ii) a portion of the remainder of the first hardened material that isbordering the second hardened material. The region may comprise anexposed surface and an interior. The exposed surface may cease toplastically deform before the interior ceases to plastically deform. Thehardening may form at least a portion of the 3D object. The at least onecontroller may be operatively coupled to the cooling member. The atleast one controller can comprise a plurality of controllers, wherein atleast two of the layer dispensing mechanism, optional cooling member andthe energy beam are controlled by different controllers. The at leastone controller can be a plurality of controllers, wherein at least twoof the layer dispensing mechanism, optional cooling member and theenergy beam are controlled by the same controller.

The controller may be operatively coupled and/or direct the function ofany of the components of the layer dispensing mechanism. The controllermay be operatively coupled to a leveling member (e.g., mechanism) and isprogrammed to direct the leveling member to level the exposed surface ofthe material bed (e.g., to form a planar exposed surface of the materialbed). The controller may be operatively coupled to a material removalmember. The controller may be operatively coupled to a materialdispensing mechanism.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct an energy beam (e.g.,along a path) to transform at least a portion of a material bed and forma 3D object comprising one or more layer portions (e.g., FIG. 11E, 1117a and 1117 b) having successive solidified melt pools of a materialwherein the 3D object comprises a surface, and interior, and a grainstructure, wherein the grain structure closer to the surface isindicative of a greater solidification rate than the grain structure inthe interior, wherein the controller is operatively coupled to thematerial bed and to the energy beam. The one or more layer portions maybe one, two or more layer portions. An example of material melt poolscan be seen in the examples in FIGS. 8A and 8B. A portions may be apart, segment, fraction, piece, and/or section.

The interior may be a symmetric interior (e.g., in the center of the 3Dobject or a cross section thereof), or an asymmetric interior. Theasymmetric interior is not in the center of the 3D object or a portionthereof. The asymmetric interior is at a side of the 3D object or asection thereof. In some examples, the interior may be close to the rimand/or surface of the 3D object.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct an energy beam (e.g.,along a path) to transform at least a portion of a material bed and forma 3D object (e.g., comprising one or more layer portions havingsuccessive solidified melt pools of a material). The 3D object maycomprise a surface, an interior, and material microstructures (e.g.,dendrites). The material microstructures closer to the surface may beindicative of a greater, smaller, or substantially similarsolidification rate than the (e.g., respective) material microstructuresin the interior. The material microstructures closer to the surface maybe indicative of a greater (e.g., swifter, quicker, and/or faster)solidification rate than the material microstructures in the interior.The at least one controller may be operatively coupled to the materialbed and to the energy beam.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct a material dispensingmechanism to dispense pre-transformed material to form a material bed(e.g., disposed adjacent to a platform), which material bed comprises afirst hardened material that includes a bottom surface facing towardsthe platform; directing a first heat (e.g., radiative) energy to heat atleast a portion (e.g., the entire portion) of the first hardenedmaterial; direct a second energy beam to transform (e.g., melt) aportion of the heated portion to form a transformed (e.g., molten)portion; direct an optional cooling member to cool the transformedportion to form a second hardened material that comprises a bottomsurface facing towards the platform. The bottom surface of the firsthardened material may have a first curvature that is higher (e.g., ofhigher value) than a second curvature of the bottom surface of thesecond hardened material. The bottom surface may have a negativecurvature when a volume bound from the bottom surface to the platform isa convex object. The bottom surface may be disposed adjacent to (e.g.,above) the platform. The first hardened material may substantiallyexclude a resin and/or a polymer. The polymer may comprise repeatingmolecular units. The polymer and/or resin may be organic. The at leastone controller may be operatively coupled to the material dispenser, thefirst heat energy, the second energy beam, and/or the cooling member.The at least one controller may comprise a plurality of controllers. Insome embodiments, at least two of the material dispenser, the first heatenergy, the second energy beam, and the cooling member are directed bythe same controller. In some embodiments, at least two of the materialdispenser, the first heat energy, the second energy beam, and thecooling member are directed by different controllers.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct an energy beam (e.g.,along a path) to transform at least a portion of a material bed into atransformed material; direct a first cooling member to cool the materialbed; and direct a second cooling member to cool the first coolingmember, wherein the at least one controller is operatively coupled tothe energy beam, the first cooling member, and the second coolingmember. The cooling member may be translatable (e.g., movable). Thetranslation may be automatic and/or manual. The translation may becontrolled (e.g., regulated and/or directed) by the controller. Thetranslation may be at predetermined times (e.g., programmed) or at awhim (e.g., spontaneous). The at least one controller may be a pluralityof controllers. In some embodiments, at least two of the energy beam,the first cooling member, and the second cooling member are directed bythe same controller. In some embodiments, at least two of the energybeam, the first cooling member, and the second cooling member aredirected by different controllers.

In another aspect, an apparatus for forming a 3D object comprises atleast one controller that is programmed to direct an energy beam totransform the at least a portion of the material bed to form the 3Dobject; direct one or more sensors to measure one or more temperatures,energy beam powers, or metrology values (e.g., heights) of one or morepoints on the at least a portion of the 3D object; and control theenergy beam with at least one processor based on the measured one ormore temperatures, energy beam powers, or metrology values. The at leastone processor may comprise at least 3 Tera floating point operations persecond, according to a benchmark. The at least one processor thatcontrols the energy beam may additionally or alternatively be based onthe geometry of the at least a portion of the 3D object. The at leastone controller may be a plurality of controllers. In some embodiments,the energy beam and the sensors are directed by different controllers.In some embodiments, the energy beam and the sensors are directed by thesame controller.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed comprising a first structure of hardened material; and anenergy source generating an energy beam, which energy source is disposedadjacent to the material bed, which energy beam transforms at least aportion of the material bed into a transformed material that couples to(e.g., attaches and/or borders) a top surface of a first structure toform a second structure, which first structure has a bottom surface witha first curvature that is negative. A bottom surface of the secondstructure may have a second curvature that is greater than the firstcurvature. The first curvature may be negative when a volume bound fromthe bottom surface to the platform is a convex object, which bottomsurface is disposed above the platform. The bottom may face theplatform. The top surface may face away from the platform. The energybeam may travel along a path while it transforms at least a portion ofthe material bed into a transformed material. The first structure may bedisposed in the material bed. The transformed material may harden into ahardened material as part of the 3D object. The transformed material maybe the hardened material as part of the 3D object. In some embodiments,the bottom (e.g., surface and/or layer) of the second structure may havea second curvature that is greater, smaller, or substantially equal tothe first curvature.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed comprising an upper layer of pre-transformed material abovea first layer of hardened material that is embedded in pre-transformedmaterial within the material bed, which material bed is disposedadjacent to a platform; and an energy source generating an energy beamgenerates a layer of hardened material from at least a portion of theupper layer of pre-transformed material (e.g., while travels along apath), wherein the first layer of hardened material is separated fromthe second layer of hardened material by a gap. The gap may comprise amaterial that is less dense than the first layer of hardened materialand/or the second layer of hardened material. The energy source may bedisposed adjacent to the material bed.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed comprising a layer of pre-transformed material on ahardened material; an energy source generating an energy beam thattransforms (e.g., melts) a portion of the layer of pre-transformedmaterial to form a transformed (e.g., molten) portion, which energysource is disposed adjacent to the material bed; a cooling member that(i) hardens the exposed surface of the transformed portion while keepingthe interior of the transformed portion in a transformed (e.g., molten)state, and/or (ii) hardens the transformed portion to form at least aportion of the 3D object. The cooling member may be disposed adjacent to(e.g., above) the material bed. The energy beam may travel along a path.The material bed may be disposed adjacent to a platform. The coolingmember may be disposed above the material bed.

Above may be relative to a direction away from the platform and/oropposite to the direction of the gravitational field.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed comprising a layer of pre-transformed material on ahardened material; an energy source generating an energy beam thattransforms (e.g., melts) a portion of the layer of pre-transformedmaterial and a portion of the first hardened material to form atransformed (e.g., molten) portion and a remainder of the first hardenedmaterial; and a cooling member that hardens the transformed portion toform a second hardened material and plastically deform a regioncomprising (i) a portion of the second hardened material, and/or (ii) aportion of the remainder of the first hardened material that isbordering the second hardened material, wherein the region comprises anexposed surface and an interior. The exposed surface may cease toplastically deform before the interior ceases to plastically deform. Theexposed surface may cease to plastically deform before, after, orsubstantially simultaneously when the interior ceases to plasticallydeform. The hardening may form at least a portion of the 3D object. Thecooling member may be disposed adjacent to the material bed. The portionof the remainder of the first hardened material may contact the secondhardened material at one or more positions. The energy beam may bedisposed adjacent to the material bed. The material bed may be disposedadjacent to a platform. The cooling member may be disposed above thematerial bed.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed comprising pre-transformed material; and an energy sourcegenerating a beam that transforms at least a portion of the material bedand forms a 3D object comprising one or more layer portions havingsuccessive solidified melt pools of a material, wherein the 3D objectcomprises a surface, and interior, and a grain structure. The grainstructure closer to the surface may be indicative of a greatersolidification rate (e.g., faster, quicker, swifter) than the grainstructure in the interior. The controller may be operatively coupled tothe material bed and/or to the energy beam. The energy beam may bedisposed adjacent to the material bed. The energy beam may travel alonga path.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed; and an energy beam that transforms at least a portion ofthe material bed and form a 3D object comprising one or more layerportions (e.g., having successive solidified melt pools of a material),wherein the 3D object comprises a surface, interior, and materialmicrostructure. The material microstructure closer to the surface may beindicative of a greater, smaller, or substantially similar hardeningrate than the (e.g., respective) material microstructure in theinterior. The material microstructure closer to the surface may beindicative of a greater hardening rate than the dendrites in theinterior. In some examples, the controller is operatively coupled to thematerial bed and to the energy beam that is disposed adjacent to thematerial bed. The hardening rate may be a solidification rate (e.g., ofthe transformed material).

In another aspect, an apparatus for forming a 3D object comprises amaterial bed disposed adjacent to a platform, which material bedcomprises a first hardened material that comprises a first bottomsurface facing towards the platform; a first energy source generating afirst heat energy that heats (e.g., but doesn't transform) at least aportion of the first hardened material, which first energy source isdisposed adjacent to the material bed; a second energy source generatinga second energy beam that transforms (e.g., melts) a portion of theheated portion to form a transformed (e.g., molten) portion, whichsecond energy source is disposed adjacent to the material bed; and anoptional cooling member that cools the transformed portion to form asecond hardened material that comprises a second bottom surface facingtowards the platform.

The cooling member may be disposed adjacent to the material bed. Thefirst bottom surface may have a first curvature that is of a highervalue than a second curvature of the second bottom surface. The firstbottom surface or second bottom surface may have a negative curvaturewhen a volume bound from the bottom surface to the platform is a convexobject. The first bottom surface and/or second bottom surface may bedisposed above the platform. The first hardened material maysubstantially exclude a resin and/or a polymer. The first bottom surfacemay have a first curvature that is of a higher, lower, or substantiallysimilar value as compared to the second curvature of the second bottomsurface. The cooling member may be disposed above the exposed surface ofthe material bed. The cooling member may be movable. For example, thecooling member may be translatable to and away from a position above thetransformed (e.g., molten) portion.

In another aspect, an apparatus for forming a 3D object comprises amaterial bed disposed in an enclosure; an energy source generating anenergy beam that travels along a path to transform at least a portion ofa material bed into a transformed material; a first cooling member that(i) cools the material bed, (ii) is movable, and/or (iii) is disposed inthe enclosure. The apparatus may further comprise a second coolingmember that cools the first cooling member and is not disposed in theenclosure.

In another aspect, an apparatus for forming a 3D object comprises anenergy beam that transforms at least a portion of a material bed to format least a portion of the 3D object; one or more sensors that measuretemperatures, energy beam power values, and/or metrology values (e.g.,heights) of one or more positions on the at least a portion of the 3Dobject, which one or more sensors are disposed adjacent to the materialbed; and at least one controller comprising at least one processor(e.g., respectively) that controls the energy beam based on the measuredone or more temperatures, energy beam power values, and/or metrologyvalues. The at least one processor may comprise at least 3 Tera floatingpoint operations per second, according to a benchmark. The at least onecontroller may be operatively coupled to the energy beam and/or to theone or more sensors. For example, a first controller is operativelycoupled to the energy beam and a second controller is coupled to the oneor more sensors. For example, the same controller is operatively coupledto the energy beam and to the one or more sensors. The at least oneprocessor may additionally or alternatively control the energy beambased on a geometry of the at least a portion of the 3D object (e.g.,position that is susceptible to deformation). The at least one processormay be included in the at least one controller that is programmed todirect an energy beam (e.g., along the path). The 3D object may beformed by hardening the transformed material. The transformed materialmay be the hardened material that comprises the 3D object.

The system and/or apparatus described herein may comprise at least oneenergy source. The first energy source may project a first energy (e.g.,first energy beam). The first energy beam may travel along a path. Thepath may be controlled and/or predetermined (e.g., by a controller). Thesystem and/or apparatus may comprise at least a second energy beam. Forexample, the first energy source may generate a plurality of energybeams (e.g., a first and a second energy beam). For example, the systemand/or may comprise at least a second energy source. The second energysource may generate a second energy (e.g., second energy beam). Thefirst and/or second energy may transform at least a portion of thepre-transformed material in the material bed to a transformed material.In some embodiments, the first and/or second energy source heat (e.g.,but not transform) at least a portion of the pre-transformed material inthe material bed. In some cases, the system can comprise 1, 2, 3, 4, 5,6, 7, 8, 9, 10, 30, 100, 300, 1000 or more energy beams and/or sources.The system can comprise an array of energy sources (e.g., laser and/ordiode array). In some embodiments, the footprint of the first and secondenergy beams on the material overlaps at least in part. In someinstances, the footprint of the first and second energy beams on thematerial may not overlap. In some examples, the first and second energybeam have a (e.g., substantially the same) similar cross-section. Insome examples, the first and second energy beam have a differentcross-section.

An energy source (e.g., FIG. 7, 716) can be a source configured todeliver energy to an area (e.g., a confined area). An energy source candeliver energy to the confined area through radiative heat transfer. Theenergy source can project energy (e.g., heat energy, and/or energybeam). The energy (e.g., beam) can interact with at least a portion ofthe material (e.g., pre-transformed and/or transformed) in the materialbed. The energy can heat the material in the material bed before, duringand/or after the material is being transformed. The energy can heat atleast a fraction of a 3D object at any point during formation of the 3Dobject. Alternatively, or additionally, the material bed may be heatedby a heating mechanism projecting energy (e.g., radiative heat and/orenergy beam). The energy may include an energy beam and/or dispersedenergy (e.g., radiator or lamp). The energy may include radiative heat.The radiative heat may be projected by a heating mechanism comprising alamp, a strip heater (e.g., mica strip heater, or any combinationthereof), a heating rod (e.g., quartz rod), or a radiator (e.g., a panelradiator). The heating mechanism may comprise an inductance heater. Theheating mechanism may comprise a resistor (e.g., variable resistor). Theresistor may comprise a varistor or rheostat. A multiplicity ofresistors may be configured in series, parallel, or any combinationthereof. In some cases, the system can have a single (e.g., first)energy source. An energy source can be a source configured to deliverenergy to an area (e.g., a confined area). An energy source can deliverenergy to the confined area through radiative heat transfer (e.g., asdescribed herein).

The energy beam may include a radiation comprising an electromagnetic,or charged particle beam. The energy beam may include radiationcomprising electromagnetic, electron, positron, proton, plasma, or ionicradiation. The electromagnetic beam may comprise microwave, infrared,ultraviolet, or visible radiation. The energy beam may include anelectromagnetic energy beam, electron beam, particle beam, or ion beam.An ion beam may include a cation or an anion. A particle beam mayinclude radicals. The electromagnetic beam may comprise a laser beam.The energy beam may comprise plasma. The energy source may include alaser source. The energy source may include an electron gun. The energysource may include an energy source capable of delivering energy to apoint or to an area. In some embodiments the energy source can be alaser source. The laser source may comprise a carbon dioxide (CO₂),neodymium-doped yttrium aluminum garnet (Nd:YAG), Neodymium (e.g.,neodymium-glass), or an Ytterbium laser. The energy source may includean energy source capable of delivering energy to a point or to an area.The energy source can provide an energy beam having an energy density ofat least about 50 joules/cm² (J/cm²), 100 J/cm², 200 J/cm², 300 J/cm²,400 J/cm², 500 J/cm², 600 J/cm², 700 J/cm², 800 J/cm², 1000 J/cm², 1500J/cm², 2000 J/cm², 2500 J/cm², 3000 J/cm², 3500 J/cm², 4000 J/cm², 4500J/cm², or 5000 J/cm². The energy source can provide an energy beamhaving an energy density of at most about 50 J/cm², 100 J/cm², 200J/cm², 300 J/cm², 400 J/cm², 500 J/cm², 600 J/cm², 700 J/cm², 800 J/cm²,1000 J/cm², 500 J/cm², 1000 J/cm², 1500 J/cm², 2000 J/cm², 2500 J/cm²,3000 J/cm², 3500 J/cm², 4000 J/cm², 4500 J/cm², or 5000 J/cm². Theenergy source can provide an energy beam having an energy density of avalue between the aforementioned values (e.g., from about 50 J/cm² toabout 5000 J/cm², from about 200 J/cm² to about 1500 J/cm², from about1500 J/cm² to about 2500 J/cm², from about 100 J/cm² to about 3000J/cm², or from about 2500 J/cm² to about 5000 J/cm²). In an example alaser can provide light energy at a peak wavelength of at least about100 nanometer (nm), 500 nm, 750 nm, 1000 nm, 1010 nm, 1020 nm, 1030 nm,1040 nm, 1050 nm, 1060 nm, 1070 nm, 1080 nm, 1090 nm, 1100 nm, 1200 nm,1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, or 2000 nm. In an example alaser can provide light energy at a peak wavelength of at most about2000 nm, 1900 nm, 1800 nm, 1700 nm, 1600 nm, 1500 nm, 1200 nm, 1100 nm,1090 nm, 1080 nm, 1070 nm, 1060 nm, 1050 nm, 1040 nm, 1030 nm, 1020 nm,1010 nm, 1000 nm, 750 nm, 500 nm, or 100 nm. The laser can provide lightenergy at a peak wavelength between any of the afore-mentioned peakwavelength values (e.g., from about 100 nm to about 2000 nm, from about500 nm to about 1500 nm, or from about 1000 nm to about 1100 nm). Theenergy beam (e.g., laser) may have a power of at least about 0.5 Watt(W), 1 W, 2 W, 3 W, 4 W, 5 W, 10 W, 20 W, 30 W, 40 W, 50 W, 60 W, 70 W,80 W, 90 W, 100 W, 120 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 500W, 750 W, 800 W, 900 W, 1000 W, 1500 W, 2000 W, 3000 W, or 4000 W. Theenergy beam may have a power of at most about 0.5 W, 1 W, 2 W, 3 W, 4 W,5 W, 10 W, 20 W, 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 120 W,150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 500 W, 750 W, 800 W, 900 W,1000 W, 1500, 2000 W, 3000 W, or 4000 W. The energy beam may have apower between any of the afore-mentioned laser power values (e.g., fromabout 0.5 W to about 100 W, from about 1 W to about 10 W, from about 100W to about 1000 W, or from about 1000 W to about 4000 W).

The powder density (e.g., power per unit area) of the energy beam may atleast about 10000 W/mm², 20000 W/mm², 30000 W/mm², 50000 W/mm², 60000W/mm², 70000 W/mm², 80000 W/mm², 90000 W/mm², or 100000 W/mm². Thepowder density of the energy beam may be at most about 10000 W/mm²,20000 W/mm², 30000 W/mm², 50000 W/mm², 60000 W/mm², 70000 W/mm², 80000W/mm², 90000 W/mm², or 100000 W/mm². The powder density of the energybeam may be any value between the aforementioned values (e.g., fromabout 10000 W/mm² to about 100000 W/mm², from about 10000 W/mm² to about50000 W/mm², or from about 50000 W/mm² to about 100000 W/mm²). Thescanning speed of the energy beam may be at least about 50 millimetersper second (mm/sec), 100 mm/sec, 500 mm/sec, 1000 mm/sec, 2000 mm/sec,3000 mm/sec, 4000 mm/sec, or 50000 mm/sec. The scanning speed of theenergy beam may be at most about 50 mm/sec, 100 mm/sec, 500 mm/sec, 1000mm/sec, 2000 mm/sec, 3000 mm/sec, 4000 mm/sec, or 50000 mm/sec. Thescanning speed of the energy beam may any value between theaforementioned values (e.g., from about 50 mm/sec to about 50000 mm/sec,from about 50 mm/sec to about 3000 mm/sec, or from about 2000 mm/sec toabout 50000 mm/sec). The energy beam may be continuous or non-continuous(e.g., pulsing). The energy beam may be modulated before and/or duringthe formation of a transformed material as part of the 3D object. Theenergy beam may be modulated before and/or during the 3D printingprocess (e.g., in real time). The energy beam may be controlled by atleast one controller.

An energy beam can be incident on, or be directed perpendicular to, thetarget surface (e.g., exposed surface of the material bed). An energybeam can be directed at an acute angle within a value of from parallelto perpendicular relative to the target surface. The energy beam can bedirected onto a specified area of at least a portion of the sourcesurface and/or target surface for a specified time period (e.g., dwelltime). The material in target surface can absorb the energy from theenergy beam and, and as a result, a localized region of the material bedcan increase in temperature. The energy beam can be moveable such thatit can translate relative to the target surface. The energy source maybe movable such that it can translate relative to the target surface.The energy beam(s) can be moved via a scanner (e.g., as disclosedherein). At least two (e.g., all) of the energy sources can be movablewith the same scanner. A least two (e.g., all) of the energy beams canbe movable with different scanners. At least two of the energy beam(s)can be translated independently of each other. In some cases, at leasttwo of the energy beam(s) can be translated at different rates (e.g.,velocities). In some cases, at least two of the energy source(s) and/orbeam(s) can be comprise at least one different characteristic. Thecharacteristics may comprise dwell time, wavelength, power, power perunit area, amplitude, trajectory, footprint (e.g., at the targetsurface), cross section, intensity, focus, or charge. The charge can beelectrical and/or magnetic charge.

The energy source can be an array, or a matrix, of energy sources (e.g.,laser array). Each of the energy sources in the array, or matrix, can beindependently controlled (e.g., by at least one control mechanism) suchthat the energy beams can be turned off and on independently. At least apart of the energy sources in the array or matrix can be collectivelycontrolled such that the at least two (e.g., all) of the energy sourcescan be turned off and on simultaneously. The energy per unit area orintensity of at least two energy sources in the matrix or array can bemodulated independently (e.g., by at least one control mechanism). Attimes, the energy per unit area (or intensity) of at least two (e.g.,all) of the energy sources in the matrix or array can be modulatedcollectively (e.g., by a control mechanism). The energy beam can scanalong the target surface by mechanical movement of the energy source(s),one or more adjustable reflective mirrors, or one or more (e.g., polygonlight) scanners. The energy source(s) can project energy using a DLPmodulator, a one-dimensional scanner, a two-dimensional scanner, or anycombination thereof. The target surface can translate vertically,horizontally, or in an angle (e.g., planar or compound). In someembodiments, the energy source is stationary (e.g., does not translate).

In some embodiments, the energy beam is modulated. For example, theenergy beam emitted by the energy source can be modulated. The modulatorcan comprise an amplitude modulator, phase modulator, or polarizationmodulator. The modulation may alter the intensity of the energy beam.The modulation may alter the current supplied to the energy source(e.g., direct modulation). The modulation may affect the energy beam(e.g., external modulation such as external light modulator). Themodulation may include direct modulation (e.g., by a modulator). Themodulation may include an external modulator. The modulator can includean aucusto-optic modulator or an electro-optic modulator. The modulatorcan comprise an absorptive modulator or a refractive modulator. Themodulation may alter the absorption coefficient of the material that isused to modulate the energy beam. The modulator may alter the refractiveindex of the material that is used to modulate the energy beam.

In some embodiments, the energy beam is translated using a scanner. Thescanner can be located in the enclosure or out of the enclosure. FIG. 7shows an example where the scanner 717 is located outside of theenclosure, and the energy beam 701 travels into the enclosure through anoptical window 718. The scanner may comprise a galvanometer scanner, apolygon, a mechanical stage (e.g., X-Y stage), a piezoelectric device,gimbal, or any combination of thereof. The galvanometer may comprise amirror. The scanner may comprise a modulator. The scanner may comprise apolygonal mirror. The scanner can be the same scanner for two or moreenergy sources and/or beams. At least two (e.g., each) energy beams mayeach have a separate scanner. The energy beams can be translatedindependently of each other. In some cases, at least two energy beamscan be translated at different rates, and/or along different paths. Forexample, the movement of the first energy source may be faster (e.g.,greater rate) as compared to the movement of the second energy source.

The systems and/or apparatuses disclosed herein may comprise one or moreshutters (e.g., safety shutters). The energy beam(s), energy source(s),and/or the platform can be moved by the scanner. The galvanometerscanner may comprise a two-axis galvanometer scanner. The scanner maycomprise a modulator (e.g., as described herein). The energy source(s)can project energy using a DLP modulator, a one-dimensional scanner, atwo-dimensional scanner, or any combination thereof. The scanner can beincluded in an optical system that is configured to direct energy fromthe energy source to a predetermined position on the target surface(e.g., exposed surface of the material bed). The controller can beprogrammed to control a trajectory of the energy source(s) with the aidof the optical system. The controller can control (e.g., regulate) asupply of energy from the energy source to the material (e.g., at thetarget surface) to form a transformed material.

The energy beam(s) emitted by the energy source(s) can be modulated. Themodulator can include an amplitude modulator, phase modulator, orpolarization modulator. The modulation may alter the intensity of theenergy beam. The modulation may alter the current supplied to the energysource (e.g., direct modulation). The modulation may affect the energybeam (e.g., external modulation such as external light modulator). Themodulation may include direct modulation (e.g., by a modulator). Themodulation may include an external modulator. The modulator can includean aucusto-optic modulator or an electro-optic modulator. The modulatorcan comprise an absorptive modulator or a refractive modulator. Themodulation may alter the absorption coefficient the material that isused to modulate the energy beam. The modulator may alter the refractiveindex of the material that is used to modulate the energy beam.

Energy (e.g., heat) can be transferred from the material bed to acooling member (e.g., heat-sink FIG. 7, 713). The cooling member canfacilitate transfer of energy away from a least a portion of apre-transformed material layer. In some cases, the cooling member can bea thermally conductive plate. The cooling member can be passive. Thecooling member can comprise a cleaning mechanism (e.g., cleaningdevice), which removes pre-transformed material and/or process debrisfrom a surface of the cooling member (e.g., to sustain efficientcooling). The debris can comprise dirt, dust, condensed material (e.g.,that result from heating, melting, evaporation and/or other processtransitions), pre-transformed material, or hardened material that didnot form a part of the 3D object. In some cases, the cleaning mechanismcan comprise a stationary rotating rod, roll, brush, rake, spatula, orblade that rotates when the heat-sinks moves in a direction adjacent tothe platform (e.g., laterally). The cleaning mechanism may comprise avertical cross section (e.g., side cross section) of a circle, triangle,square, pentagon, hexagon, octagon, or any other polygon. The verticalcross section may be of an amorphous shape. In some cases, the cleaningmechanism rotates when the cooling member moves (e.g., in a directionthat is not lateral). In some cases, the cleaning mechanism rotateswithout or irrespective of a movement of the cooling member. In somecases, the cooling member comprises at least one surface that is coatedwith a layer that prevents debris from coupling (e.g., attaching) to theat least one surface (e.g., an anti-stick layer).

One or more temperature sensors (e.g., as described herein) can sensethe temperature of the cooling member. The cooling member can comprisetwo or more thermally conductive plates. The cooling member can be madefrom a thermally conductive material, for example a metal or metalalloy. The cooling member can comprise copper or aluminum. The coolingmember (e.g., heat-sink) can comprise a material that conducts heatefficiently. The efficient heat conductivity may be at least about 20Watts per meter times degrees Kelvin (W/mK), 50 W/mK, 100 W/mK, 150W/mK, 200 W/mK, 205 W/mK, 300 W/mK, 350 W/mK, 400 W/mK, 450 W/mK, 500W/mK, 550 W/mK, 600 W/mK, 700 W/mK, 800 W/mK, 900 W/mK, or 1000 W/mK.The efficient heat conductivity may of any value between theaforementioned values (e.g., from about 400 W/mK to about 1000 W/mK, orfrom about 20 W/mK to about 500 W/mK). The efficient heat conductivitycan be measured at ambient temperatures (e.g., R.T. or 20° C.). Thecooling member (e.g., heat-sink) can comprise an elemental metal or ametal alloy. The cooling member can disclose a material as disclosedherein. For example, the cooling member can comprise elemental metal,metal alloy, ceramic, an allotrope of elemental carbon, or a polymer.For example, the cooling member can comprise stone, zeolite, clay orglass. The cooling member (e.g., 713) can be placed above the topsurface (e.g., 708) of the material bed (e.g., 704). The cooling membercan be placed below, to the side, or above the exposed surface of thematerial bed. In some cases, the cooling member can contact a surface(e.g., top surface) of the material bed. The cooling member can justtouch the surface of the material bed. The cooling member can apply acompressive force to the exposed surface of the material bed. In somecases, the cooling member extends up to, or past, the edges of the topsurface of the material bed. The cooling member can facilitate atransfer of energy from at least a portion of a material (e.g., powder)layer without substantially changing and initial configuration of thepre-transformed material in the material bed. In some cases, thematerial (e.g., powder) layer can comprise a fully or partially formed3D object. The cooling member can facilitate the transfer of energy fromat least a portion of a material (e.g., powder) layer withoutsubstantially altering the position of the printed 3D object (or a partthereof) by any of the position alteration values disclosed herein.

The cooling member may comprise a heat transfer member that enablesheating, cooling or maintaining the temperature of the material bedand/or of the 3D object being formed in the material bed. In someexamples, the heat transfer member is a cooling member that enables thetransfer of energy out of the material bed. The heat transfer member canenable the transfer of energy to the material bed (e.g., at specifiedtimes).

Heat can be transferred from the material bed (e.g., directly orindirectly) to the cooling member through any one or combination of heattransfer mechanisms (e.g., conduction, natural convection, assistedconvection, and radiation). The cooling member can be solid, liquid orsemi-solid. In some examples, the heat-sink is solid. The cooling membermay comprise a gas, liquid, or solid. Alternatively, the cooling membercan comprise one or more openings. The openings can be arranged in apattern or randomly. For example, the openings can be arranged in astriped pattern or a chessboard pattern. In some cases, material (e.g.,powder) removal openings (e.g., suction nozzles) can be adjacent to theopenings of the cooling member. In an example, the cooling member can bea plate. In some cases, at least as about 5%, 10%, 20%, 30%, 40%, 50%,60% or 70% of the surface area of the cooling member can be an openingor hole. The holes or openings can be configured to allow the first andthe optional second energy sources to access the powder layer.

In the example shown in FIG. 5A, a first cooling member (e.g.,heat-sink) 513 is a disposed at a distance from the exposed surface ofthe material bed 504, which distance constitutes a gap. The coolingmember can be separated from the material bed by a gap. The gap can havea variable or adjustable spacing. The cooling member can be controlled(e.g., regulated and/or directed) by a controller (e.g., comprising aprocessor). The gap can be adjusted by a controller and/or manually. Forexample, the gap can be adjusted based on an energy per unit area thatis suitable to transform at least a portion of the material bed.Alternatively or additionally, the cooling member can contact thematerial bed. In some instances, the cooling member can be alternatelyand/or sequentially brought in contact with the material bed.

The distance between the cooling member and the material bed (e.g.,exposed surface thereof) can influence the heat transfer between thecooling member and the material bed. The vertical distance of the gapfrom the exposed surface of the material bed may be at least about 50μm, 100 μm, 250 μm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8mm, 9 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm,or 100 mm. The vertical distance of the gap from the exposed surface ofthe powder bed may be at most about 50 μm, 100 μm, 250 μm, 0.5 mm, 1 mm,2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 20 mm, 30 mm, 40mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm. The vertical distanceof the gap from the exposed surface of the powder bed may be any valuebetween the aforementioned values (e.g., from about 50 μm to about 100mm, from about 50 μm to about 60 mm, or from about 40 mm to about 100mm). In some instances, there is no gap (i.e., the gap is zero). In somecases, the gap can be adjustable. The cross section of the gap can becontrolled by a controller and/or manually. The gap can have asubstantially uniform dimension across the entire cooling member, and/oracross the material bed. In some cases, the gap distance can vary acrossthe material bed. The gap can be adjusted such that the cooling memberis in contact with the material bed (e.g., the exposed surface of thematerial bed). A translation mechanism can be used to (e.g., dynamicallyor flexibly) move the cooling member, for example, in and out of contactwith the material bed. For example, a translation mechanism can be usedto move the cooling member in and out of a position above the materialbed. The translation mechanism can be manually and/or electronicallycontrolled (e.g., by the controller). In an example, the translationmechanism can be an array of curved leaf springs, flexible needlesprings, or a set of rolling cylinders. The contact pressure between thecooling member (e.g., plate) and the material bed can be electronicallyand/or manually adjusted.

In some embodiments, the gap is filled with at least one gas. Thegas(es) can be chosen in order to achieve a specific heat transferproperty between the material bed and the cooling member. For example, agas(es) with high thermal conductivity can be chosen to increase therate of conductive heat transfer from the material bed to the coolingmember. The gases can be air. The gas can be non-reactive (e.g., inert).The gases may constitute an atmosphere. The gas can by any gas mentionedherein. For example, the gas can comprise argon, nitrogen, helium, neon,krypton, xenon, hydrogen, carbon monoxide, carbon dioxide, or oxygen. Insome cases, the system and/or apparatus can be stored and operated in avacuum chamber in which case there will be at most a thin layer (e.g.,as compared to ambient atmosphere) between the cooling member and thematerial bed. The cooling member can be thermally coupled to thematerial bed through the layer of the gas. A metrological sensor (e.g.,distance sensor or height sensor) can measure the distance of the gasgap. For example, a gas with high thermal conductivity can be chosen.The gas gap can be an environment between the cooling member and anexposed surface of the material bed. The size of the gap may becontrolled (e.g., manually or electronically). The control may be duringand/or before the 3D printing. In some cases, turbulent, rotational,and/or laminar gas flow currents can be generated in the gap. Thelaminar gas flow can be parallel to the average surface of the materialbed. The currents can increase, or aid convective heat transfer betweenthe material bed and the cooling member. In some cases, the currents canbe driven by movement of the cooling member with structures (e.g.,periodic wedges) present along the cooling member to direct the currents(e.g., towards the material bed, or in a direction parallel to thematerial bed). The wedges can be periodically spaced along a surface ofthe cooling member with a spacing distance from about 1 μm to about 100mm, or from about 10 μm to about 10 mm. Alternatively or additionally, aconvective current can be generated in the gas gap by forcing a gas flowin the gap. The gas flow can be forced by a first array or matrix ofopening ports (e.g., nozzles) embedded in the cooling member (e.g., inthe surface of the cooling member). The opening ports can be orientedtowards an exposed surface of the material bed and may allow gas to flowin to the gap (e.g., via release of a pressurized gas). A second arrayor matrix of opening ports can remove the gas introduced by the firstarray or matrix of opening ports to create gas flow (e.g., via vacuummechanism).

In some cases, at least one gas bearing is utilized to increase thecooling rate of the material bed. In this embodiment a planar (e.g.,laminar) gas bearing can be created using a set of openings in thecooling plate (e.g., which openings face the material bed). Pressurizedgas can be injected from one set of openings to the gap. The pressurizedgas may leave the gap through a second set of openings. The gas bearingcan induce forced convection. The gas bearing may increase the heattransfer rate from the material bed. In another example, thermo-acousticheat extraction can be used to increase the cooling rate of the powderbed.

In some cases, the cooling member can comprise a heat exchanger. Theheat exchanger (e.g., comprising a thermostat) can be configured tomaintain the temperature of the cooling member at a constant targettemperature. In some cases, the target temperature (e.g., of the heatsink, heat exchanger, and/or material bed during the 3D printing) can behigher than, lower than, or substantially equivalent to the ambienttemperature. The heat exchanger can circulate a cooling fluid through aplumbing system. The plumbing system can be embedded in the coolingmember. The plumbing system can be embedded in a position different fromthe cooling member. The plumbing system may comprise one or morechannels (e.g., pipe, or coil). The cooling fluid (e.g., coolant) can beconfigured to absorb heat from the cooling member through any one orcombination of heat transfer mechanisms (e.g., conduction, naturalconvection, forced convection, and radiation). In some examples, thecooling member is not embedded within the material bed (e.g., in a formof pipes). In some examples, the cooling member (e.g., FIG. 5A, 512) isdistant from the material bed (e.g., FIG. 5A, 504).

In some examples, the heat exchanger may be an integral part of thecooling member. At times, the heat exchanger may be separated from thecooling member. For example, the heat exchanger may be disposed at alocation that is different than the location of the cooling member. Forexample, the cooling member can be disposed within the enclosure, andthe heat exchanger can be disposed outside of the enclosure. The heatexchanger may be included in a second cooling member. FIG. 5A shows anexample of a second cooling member that comprises a heat exchanger 512having channels (e.g., tubing) 516 and 514 that facilitate rapid flow ofheat away from the enclosure 507. The second cooling member (e.g.,comprising 512) is not disposed within the enclosure 507. The firstcooling member 513, is disposed within the enclosure 507. The firstcooling member may be moveable. Movable may comprise movable laterally,horizontally, at an angle (planar or compound), or any combinationthereof. FIG. 5A shows an example of one position of the first coolingmember (e.g., 513), and FIG. 5B shows an example of a second position ofthe first cooling member (e.g., 533) in which it contacts the secondcooling member 532 (e.g., directly or through a wall of the enclosure).The first cooling member can be designated as an internal coolingmember, as it is located within the enclosure. The second cooling membercan be designated as an external cooling member, when it is locatedoutside the enclosure, or when it (or any part thereof) forms a part ofthe body of the enclosure (e.g., wall, rim and/or coating of theenclosure). The second cooling member may be part to the enclosure wall,coating, and/or rim. The second cooling member (or parts thereof) can bemovable or stationary. The first and/or second cooling member may becontrolled by the controller and/or manually. The first and/or secondcooling member (or parts thereof) can be replaceable.

The external cooling member may comprise one or more channels. Thechannels may comprise channels within a stationary structure (e.g., ablock of material), or channels that are external to the stationarystructure. The channels may comprise pipes. At least a portion of thechannel may be open or closed. FIG. 5A shows an example of a verticalcross section (e.g., 517) of a stationary structure 512 as part of thecooling member that is not disposed within the enclosure 507; and anexample of channels (e.g., 514 and 516) that are external to thestationary structure 512. The interior of the channels may comprise acooling gas, liquid, semi-solid (e.g., gel), or solid (e.g., powder).The interior of the channels may be movable, transferable, and/orflowing. The interior of the channels may comprise a substance that isable to transport and/or evacuate heat. For example, the substancewithin the channels may have a high specific heat capacity. For example,the substance within the channels may be transportable (e.g., liquid, orgas). The specific heat of the substance within the channels may be atleast 1 Kilo-Joule per Kilogram time degrees Kelvin (kJ/kg K), 1.5 kJ/kgK, 2 kJ/kg K, 2.5 kJ/kg K, 3 kJ/kg K, 3.5 kJ/kg K, 4 kJ/kg K, or 4.5kJ/kg K. The specific heat of the substance within the channels may beany value between the afore-mentioned values (e.g., from about 1 kJ/kg Kto about 4.5 kJ/kg K, from about 2 kJ/kg K to about 4.5 kJ/kg K, or fromabout 3 kJ/kg K to about 4.5 kJ/kg K). The substance within the channelsmay be a coolant. The coolant may comprise water, ethylene glycol,diethylene glycol, propylene glycol, Betaine, silicon oil, mineral oil(e.g., castor oil), transfer oil, fluorocarbon oil, Freon, fuel (e.g.,jet fuel, Kerosene), refrigerant (R-12, R-22, and/or R-134a), ammonia,sulfur dioxide, carbon dioxide, or propane. The substance within thechannels may comprise liquid fusible alloys (e.g., NaK, lead-bismuthalloy, or molten salt (e.g., NaF—NaBF₄, FLiBe, or FLiNaK). The coolantmay comprise a liquid gas. The coolant may comprise a nanofluid (e.g.,comprising nanoparticles).

The first cooling member may contact the second cooling member. Thecontact may be a direct contact. The contact may be in indirect contact.The indirect contact may be through one or more material. The one ormore material may constitute the casing of the enclosure (e.g., 507).The contact may be effectuated using a physical, magnetic, electrical,or hydraulic force. For example, the internal cooling member maycomprise a material that is magnetically and/or electrically attractedto the force exerted adjacent to the position where the external coolingmember is disposed. The force can be exerted by the external coolingmember. Additionally, or alternatively, the force may be exerted by aforce generator located adjacent to the external cooling member. Forexample, the force generator can comprise an electrostatic forcegenerator, electric field generator, or an electrical conductor (e.g.,an electrode). The electric field generator may comprise a magnet. Theelectric field generator may comprise time varying magnetic fields. Theforce generator can comprise a magnet, or a magnetic force generator.The force generator can be a vacuum exit port (e.g., nozzle). The forcegenerator can be located in or adjacent to the coating, and/or rim ofthe enclosure. The coating may comprise a surface of the enclosure. Thegenerated force may be located such that the internal cooling member maycouple (e.g., attach) itself to a specified position adjacent to theexternal cooling member. The external cooling member may couple (e.g.,attach) itself due to its response to being attracted to the generatedforce. For example, the external cooling member may contain a metal thatis attracted to the magnetic field exerted by a magnet located on thesecond cooling member. Additionally, or alternatively, the force may bea chemical force (e.g., chemical attraction). The chemical attractionmay be based on polarity based attraction and/or complexation.

In some examples, the enclosure comprises two or more cooling memberswithin the enclosure (e.g., internal cooling members). In some examples,more than one (e.g., two or more) cooling member is disclosed not withinthe enclosure (e.g., external cooling members). FIG. 18A shows anexample of a system an apparatuses showing an external cooling member1812 and two internal cooling members (e.g., 1813 and 1818). In someexamples, a first internal cooling member (e.g., 1813) is being cooledwith the aid of an external cooling member (e.g., 1812), while a secondinternal cooling member (e.g., 1818) absorbs heat from the material bed(e.g. 1804). In some examples, a first cooling member is being cooledwith the aid of an external cooling member, while a second internalcooling member absorbs heat (e.g., that is dissipated during the 3Dprinting process). The cooling member that is being cooled with the aidof an external cooling member can be used as a heat depleting coolingmember. The internal cooling member that absorbs heat from the materialbed can be a heat absorbing cooling member (e.g., a working coolingmember). When the first internal cooling member is sufficiently cooledand/or when the second internal cooling member reaches a maximum heatingcapacity, the second internal cooling member may become the heatdepleting cooling member as it is being cooled with the aid of anexternal cooling member, while the first internal cooling member maybecome the heat absorbing cooling member as it absorbs heat from thematerial bed. When the heat absorbing cooling member reaches a maximumtemperature and/or when the heat depletion cooling reaches a minimumtemperature, the functions (e.g., and positions) of the internal coolingmembers may interchange. FIG. 18B shows an example of a system and/orapparatuses showing an external cooling member 1832 and two internalcooling members (e.g., 1833 and 1838). FIG. 18B represents a secondposition of the cooling members shown in FIG. 18A. In FIG. 18B, the heatabsorbing cooling member 1818 of FIG. 18A, became the heat depletingcooling member 1833; and the heat depleting cooling member 1813 of FIG.18A, became the heat absorbing cooling member 1838 of FIG. 18B.

In some embodiments, various parameters of the cooling member arecontrolled. The maximal temperature of the heat absorbing cooling memberand/or minimal temperature of the heat depleting cooling member may becontrolled (e.g., regulated). The control may be manual and/orautomatic. For example, the control may be by a controller (e.g., usingat least one temperature sensor). The position of the first and/orsecond internal cooling member may be controlled (e.g., regulated and/ordirected) by the controller and/or manually. The position of the firstand/or second external cooling member may be controlled (e.g., regulatedand/or directed) manually and/or by the controller. The rate of movingthe coolant in the external cooling member may be controlled manuallyand/or by the controller. The maximal temperature of the heat absorbingcooling member may be below a transformation temperature (e.g., meltingpoint) of at least one material within the heat absorbing coolingmember. The minimal temperature of the heat depleting cooling member maybe above a temperature causing substantial number of defects (e.g.,cracks) in the heat depleting cooling member. Substantial number ofdefects may be relative to the intended purpose. The cooling member andany of its characteristics can be those disclosed in in ProvisionalPatent Application Ser. No. 62/396,584, that is incorporated herein byreference in its entirety.

The position of the internal cooling member adjacent (e.g., next) to theexternal cooling member may be reversible. The internal cooling membermay be detached from the external cooling member. The detachment may bedue to a force (e.g., as disclosed herein). The detachment may be due toa repelling force. For example, the electrical force generator mayreverse its charge and cause repulsion of the internal cooling memberfrom the position adjacent to the external cooling member. The forcegenerator may be controlled manually and/or by the controller. Forexample, the controller may control (e.g., direct and/or regulate) themagnitude and polarity of the force generated by the force generator.Additionally, or alternatively, the internal cooling member may bemechanically brought to and/or taken away from a position adjacent tothe external cooling member. The mechanical position manipulation (e.g.,translation) of the internal cooling member may be controlled by thecontroller. The translation of the internal cooling member may beeffectuated by a scanner, motor, force generator, or any combinationthereof. The positioning (e.g., translation) of the internal coolingmember may be triggered by the temperature of the internal and/orexternal cooling member, by the position of the energy beam, or by theposition of the layer dispensing mechanism (or any of its components).The translation of the internal cooling member may be programmed. Thetranslation of the internal cooling member may be according to analgorithm. The algorithm may incorporate the 3D model of the 3D object.An example of a layer dispensing mechanism is disclosed in applicationnumber PCT/US15/36802, titled “Apparatuses, Systems and Methods for 3DPrinting,” that was filed on Jun. 19, 2015 that is incorporated hereinby reference in its entirety.

The specified position of the internal cooling member adjacent to theexternal cooling member may effectuate an efficient (e.g., optimal) heattransfer between the internal cooling member and the external coolingmember. The efficient heat transfer may be able to cool the internalcooling member by about 100° C. in at most 2 seconds (sec), 10 sec, 30sec, 1 minute (min), 5 min, 10 min, or 30 min. The efficient heattransfer may be able to cool the internal cooling member by about 100°C. in any value between the aforementioned values (e.g., from about 2secs to about 30 min, from about 2 secs to about 5 min, from about 2secs to about 30 sec).

The cooling member has a shape. The cooling member can be a plate. Theplate may contact the surface of the material bed along a planardimension. The plate may contact the surface of the enclosure (e.g.,coating of the enclosure). In some cases, the cooling member can be aone or more cylinder that roll along the surface (e.g., of the materialbed or of the enclosure). Alternatively, or additionally, the coolingmember can be a belt that runs along the surface. The cooling member cancomprise spikes, ridges, or other protrusions features configured topenetrate into a surface. For example, the protrusions features may beconfigured to penetrate the material bed to enhance cooling surface areaand depth. The protruding features may be bendable (e.g., soft) ornon-bendable (e.g., stiff). The protrusion features may be configured tofit into grooves within the coating of the enclosure. The grooves mayfacilitate efficient transfer of heat from the internal cooling memberto the external cooling member.

In some instances, the cooling member does not reside within thematerial bed. In other examples, the cooling member may reside at leastpartially within the material bed. The cooling member can be a duct or apipe. In some instances, the cooling member is not a plate or a slab.The cooling member can be a cooled layer of pre-transformed material.The cooled pre-transformed (e.g., powder) layer can act as a coolingmember.

A thermal control unit (e.g., a cooling member such as a heat-sink or acooling plate, a heating plate, or a thermostat) can be provided insideof the region where the 3D object is formed or adjacent to the regionwhere the 3D object is formed. The thermal control unit can be providedoutside of the region where the 3D object is formed (e.g., at apredetermined distance). The thermal control unit can be provided withinthe enclosure (e.g., outside of the enclosure). The thermal control unitmay be in physical contact with at least a portion of the enclosure. Insome cases, the thermal control unit can form at least one section of aboundary region where the 3D object is generated (e.g., the containeraccommodating the material bed).

A cooling of a layer within the material bed can occur by energytransfer from the layer to a cooling member. Energy can be transferredfrom the layer along a direction that is oriented away from the materialbed. In some cases, energy can be transferred in a direction toward asurface of the cooling member (e.g., a surface of the internal coolingmember). The energy can be transferred in the direction of the exposedsurface of the material bed. The energy can be transferred upwards(e.g., in a direction opposite to the building platform). The energy canbe transferred to a cooling member (e.g., internal) located above thematerial bed, or to the side of the material bed. At times, at leastabout 20%, 30%, 40%, 50%, 60%, 70%, 70%, 80%, 90%, or 95% of the energy(e.g., heat) is transferred towards the cooling member. At times, atmost about 99%, 95%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 30%, or 20% ofthe energy is transferred towards the cooling member. Sometimes, theenergy transferred towards the cooling member can have a percentagevalue between any of the aforementioned percentage values (e.g., fromabout 20% to about 99%, from about 20% to about 60%, from about 50% toabout 99%).

The cooling member can cool and/or stabilize the temperature of theportion of the material bed and/or at least a portion of the remainderof the material bed that did not transform to form the 3D object(referred to herein as the “remainder”). The cooling member can beconfigured to remove energy at a rate greater than or equal to about P₁.The cooling member can be maintained at a temperature that issubstantially lower than the temperature of the material bed.

In some embodiments, the cooling member cools the material bed duringthe 3D printing. The cooling member can be adapted to be selectivelypositioned between the material bed (or the container accommodating thematerial bed) and the energy source(s). The cooling member can beadapted to be selectively positioned between the platform and the energysource(s). The cooling member can be adapted to be selectivelypositioned along the vector of the energy beam (e.g., FIG. 7, 701). Insome cases, an actuator (e.g., motor) translates the cooling member suchthat the hole(s) remains in a location that allows the energy beam(s) toaccess the material bed as it is scanned across it. In some examples,the actuator that controls movement of the cooling member issynchronized with the at least one scanner to permit articulation of theenergy source(s). The cooling member can controllably track energyapplied to the portion of the material from the energy source(s).Movement of the cooling member can be controlled manually and/or by acontroller. The controller (e.g., computer) can be programmed to controlmovement of the cooling member. In some cases, the controller isprogrammed to optimize the removal of energy from the material bed.Optimizing removal of energy from the material bed (e.g., before and/orduring the 3D printing) can include changing the gap length or width,moving the cooling member, initiating a forced convection system (e.g.,fan), adjusting gas composition, any combination thereof, or any otherprocess that can influence time or efficiency variables of producing the3D object. The controller can be further programmed to control (e.g.,before and/or during the 3D printing) a temperature profile of theplatform separate from a temperature profile of the material bed. Insome instances, the controller is programmed to ensure uniform heattransfer away from the material bed. For example, the controller can beprogrammed to ensure that regions of the material bed surface arecovered by solid portions and open (hole) portions of the cooling memberfor equal durations of time to maintain uniform heat transfer away fromthe material bed. In some cases, the cooling member can be substantiallytransparent. Before and/or during the 3D printing comprises beforeand/or during formation of a layer of transformed material.

In some examples, one or more sensors (e.g., metrology sensors) detectthe topology of the exposed surface of the material bed and/or theexposed surface of the 3D object or any part thereof. The sensor candetect the amount of material deposited in the material bed. The sensorcan be a proximity sensor. For example, the sensor can detect the amountof pre-transformed material deposited on the exposed surface of amaterial bed. The sensor can detect the amount of material dispensed bythe material dispensing mechanism. The sensor can detect the amount ofmaterial relocated by a leveling mechanism. The sensor can detect thetemperature of the material. For example, the sensor may detect thetemperature of the material in a material (e.g., powder) dispensingmechanism, and/or in the material bed. The sensor may detect thetemperature of the material during and/or after its transformation. Thesensor may detect the temperature and/or pressure of the atmospherewithin an enclosure (e.g., chamber). The sensor may detect thetemperature of the material bed at one or more locations.

In some embodiments, the at least one sensor is operatively coupled toat least one controller. The sensor may comprise light sensor, acousticsensor, vibration sensor, chemical sensor, electrical sensor, magneticsensor, fluidity sensor, movement sensor, speed sensor, position sensor,pressure sensor, force sensor, density sensor, distance sensor, orproximity sensor. The sensor may include temperature sensor, weightsensor, material (e.g., powder) level sensor, metrology sensor, gassensor, or humidity sensor. The metrology sensor may comprisemeasurement sensor (e.g., height, length, width, angle, and/or volume).The metrology sensor may comprise a magnetic, acceleration, orientation,or optical sensor. The sensor may transmit and/or receive sound (e.g.,echo), magnetic, electronic, or electromagnetic signal. Theelectromagnetic signal may comprise a visible, infrared, ultraviolet,ultrasound, radio wave, or microwave signal. The metrology sensor maymeasure the tile. The metrology sensor may measure the gap. Themetrology sensor may measure at least a portion of the layer ofmaterial. The layer of material may be a pre-transformed material (e.g.,powder), transformed material, or hardened material. The metrologysensor may measure at least a portion of the 3D object. The gas sensormay sense any of the gas delineated herein. The distance sensor can be atype of metrology sensor. The distance sensor may comprise an opticalsensor, or capacitance sensor. The temperature sensor can compriseBolometer, Bimetallic strip, calorimeter, Exhaust gas temperature gauge,Flame detection, Gardon gauge, Golay cell, Heat flux sensor, Infraredthermometer, Microbolometer, Microwave radiometer, Net radiometer,Quartz thermometer, Resistance temperature detector, Resistancethermometer, Silicon band gap temperature sensor, Special sensormicrowave/imager, Temperature gauge, Thermistor, Thermocouple,Thermometer (e.g., resistance thermometer), or Pyrometer. Thetemperature sensor may comprise an optical sensor. The temperaturesensor may comprise image processing. The temperature sensor maycomprise a camera (e.g., IR camera, CCD camera). The pressure sensor maycomprise Barograph, Barometer, Boost gauge, Bourdon gauge, Hot filamentionization gauge, Ionization gauge, McLeod gauge, Oscillating U-tube,Permanent Downhole Gauge, Piezometer, Pirani gauge, Pressure sensor,Pressure gauge, Tactile sensor, or Time pressure gauge. The positionsensor may comprise Auxanometer, Capacitive displacement sensor,Capacitive sensing, Free fall sensor, Gravimeter, Gyroscopic sensor,Impact sensor, Inclinometer, Integrated circuit piezoelectric sensor,Laser rangefinder, Laser surface velocimeter, LIDAR, Linear encoder,Linear variable differential transformer (LVDT), Liquid capacitiveinclinometers, Odometer, Photoelectric sensor, Piezoelectricaccelerometer, Rate sensor, Rotary encoder, Rotary variable differentialtransformer, Selsyn, Shock detector, Shock data logger, Tilt sensor,Tachometer, Ultrasonic thickness gauge, Variable reluctance sensor, orVelocity receiver. The optical sensor may comprise a Charge-coupleddevice, Colorimeter, Contact image sensor, Electro-optical sensor,Infra-red sensor, Kinetic inductance detector, light emitting diode(e.g., light sensor), Light-addressable potentiometric sensor, Nicholsradiometer, Fiber optic sensors, Optical position sensor, Photodetector, Photodiode, Photomultiplier tubes, Phototransistor,Photoelectric sensor, Photoionization detector, Photomultiplier, Photoresistor, Photo switch, Phototube, Scintillometer, Shack-Hartmann,Single-photon avalanche diode, Superconducting nanowire single-photondetector, Transition edge sensor, Visible light photon counter, or Wavefront sensor. The weight of the material bed can be monitored by one ormore weight sensors in, or adjacent to, the material. For example, aweight sensor in the material bed can be at the bottom of the materialbed. The weight sensor can be between the bottom of the enclosure (e.g.,FIG. 7, 711) and the substrate (e.g., FIG. 7, 709) on which the base(e.g., FIG. 7, 702) or the material bed (e.g., FIG. 7, 704) may bedisposed. In some examples, the one or more sensors can sense the levelof the exposed surface of the material bed. The material (e.g., powder)level sensor can be in communication with a material dispensingmechanism (e.g., powder dispenser), energy source, scanner, and/orenergy beam. One or more position sensors (e.g., height sensors) canmeasure the height of the material bed (e.g., relative to the platform).The position sensors can be optical sensors. The position sensors candetermine a distance between one or more energy beams (e.g., a laser oran electron beam.) and a surface of the material bed and/or 3D object ora portion thereof. The one or more sensors may be connected to at leastone controller (e.g., to a processor, to a computer).

The systems, apparatuses, and/or methods described herein can comprise amaterial recycling mechanism. The recycling mechanism can collect unusedpre-transformed material and return the unused pre-transformed materialto a reservoir of a material dispensing mechanism (e.g., the materialdispensing reservoir), or to the bulk reservoir that feeds the materialdispensing mechanism. Unused pre-transformed material may be materialthat was not used to form at least a portion of the 3D object. At leasta fraction of the pre-transformed material removed from the material bedby the leveling mechanism and/or material removal mechanism can berecovered by the recycling system. At least a fraction of the materialwithin the material bed that did not transform to subsequently form the3D object can be recovered by the recycling system. A vacuum nozzle(e.g., which can be located at an edge of the material bed) can collectunused pre-transformed material. Unused pre-transformed material can beremoved from the material bed without vacuum. Unused pre-transformed(e.g., powder) material can be removed from the material bed manually.Unused pre-transformed material can be removed from the material bed bypositive pressure (e.g., by blowing away the unused material). Unusedpre-transformed material can be removed from the material bed byactively pushing it from the material bed (e.g., mechanically or using apositive pressurized gas). A gas flow can direct unused pre-transformedmaterial to the vacuum nozzle. A material collecting mechanism (e.g., ashovel) can direct unused material to exit the material bed (andoptionally enter the recycling mechanism). The recycling mechanism cancomprise one or more filters to control a size range of the particlesreturned to the reservoir. In some cases, a Venturi scavenging nozzlecan collect unused material. The nozzle can have a high aspect ratio(e.g., at least about 2:1, 5:1, 10:1, 20:1, 30:1, 40:1, or 100:1) suchthat the nozzle does not become clogged with material particle(s). Insome embodiments, the material may be collected by a drainage mechanismthrough one or more drainage ports that drain material from the materialbed into one or more drainage reservoirs. The material in the one ormore drainage reservoirs may be re used (e.g., after filtration and/orfurther treatment).

In some cases, unused material can surround the 3D object in thematerial bed. The unused material can be substantially removed from the3D object. Substantial removal may refer to material covering at mostabout 20%, 15%, 10%, 8%, 6%, 4%, 2%, 1%, 0.5%, or 0.1% of the surface ofthe 3D object after removal. Substantial removal may refer to removal ofall the material that was disposed in the material bed and remained asmaterial at the end of the 3D printing process (i.e., the remainder),except for at most about 10%, 3%, 1%, 0.3%, or 0.1% of the weight of theremainder. Substantial removal may refer to removal of all the remainderexcept for at most abbot 50%, 10%, 3%, 1%, 0.3%, or 0.1% of the weightof the printed 3D object. The unused material can be removed to permitretrieval of the 3D object without digging through the material bed. Forexample, the unused material can be suctioned out of the material bed byone or more vacuum ports (e.g., nozzles) built adjacent to the materialbed, by brushing off the remainder of unused material, by lifting the 3Dobject from the unused material, by allowing the unused material to flowaway from the 3D object (e.g., by opening an exit opening port on theside(s) or on the bottom of the material bed from which the unusedmaterial can exit). After the unused material is evacuated, the 3Dobject can be removed and the unused material can be re-circulated to amaterial reservoir for use in future builds.

In some embodiments, the platform may comprise a mesh. The base and/orsubstrate may comprise a mesh. The 3D object can be generated on a mesh.The mesh holes can be blocked. The mesh holes can be open-able (e.g., bya controller and/or manually). A solid platform (e.g., base orsubstrate) can be disposed underneath the mesh such that the materialstays confined in the material bed and the mesh holes are blocked. Theblocking of the mesh holes may not allow a substantial amount ofmaterial to flow through. The mesh can be moved (e.g., vertically or atan angle) relative to the solid platform by pulling on one or more postsconnected to either the mesh or the solid platform (e.g., at the one ormore edges of the mesh or of the base) such that the mesh becomesunblocked. The one or more posts can be removable from the one or moreedges by a threaded connection. The mesh substrate can be lifted out ofthe material bed with the 3D object to retrieve the 3D object such thatthe mesh becomes unblocked. Alternatively, or additionally, the platformcan be tilted, horizontally moved such that the mesh becomes unblocked.The platform can include the base, substrate, or bottom of theenclosure. When the mesh is unblocked, at least part of thepre-transformed material flows from the material bed through the meshwhile the 3D object remains on the mesh. In some instances, two meshesmay be situated such that in one position their holes are blocked, andin the other position, opened. The 3D object can be built on a constructcomprising a first and a second mesh, such that at a first position theholes of the first mesh are completely obstructed by the solid parts ofthe second mesh such that no material can flow through the two meshes atthe first position, as both mesh holes become blocked. The first mesh,the second mesh, or both can be controllably moved (e.g., horizontallyor in an angle) to a second position. In the second position, the holesof the first mesh and the holes of the second mesh are at leastpartially aligned such that the material disposed in the material bed isable to flow through to a position below the two meshes, leaving theexposed 3D object.

In some cases, cooling gas can be directed to the hardened material(e.g., 3D object) for cooling the hardened material during and/orfollowing its retrieval. The mesh can be of a size such that the unusedmaterial will sift through the mesh as the 3D object becomes exposedfrom the material bed. In some cases, the mesh can be coupled (e.g.,attached) to a pulley or other mechanical device such that the mesh canbe moved (e.g., lifted) out of the material bed with the 3D part.

In some cases, a layer of the 3D object is formed within at most about 1hour (h), 30 minutes (min), 20 min, 10 min, 5 min, 1 min, 40 seconds(s), 20 s, 10 s, 9 s, 8 s, 7 s, 6 s, 5 s, 4 s, 3 s, 2 s, or 1 s. A layerof the 3D can be formed within any time between the aforementioned timescales (e.g., from about 1 h to about 1 s, from about 10 min to about 1s, from about 40 s to about 1 s, from about 10 s to about 1 s, or fromabout 5 s to about 1 s).

In some examples, the generated 3D object requires very little or nofurther processing after its retrieval. In some examples, the diminishedfurther processing or lack thereof, will afford a 3D printing processthat requires smaller amount of energy and/or less waste as compared tocommercially available 3D printing processes. The smaller amount can besmaller by at least about 1.1, 1.3, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10.The smaller amount may be smaller by any value between theaforementioned values (e.g., from about 1.1 to about 10, or from about1.5 to about 5). Further processing may comprise trimming, as disclosedherein. Further processing may comprise polishing (e.g., sanding) ortrimming. For example, in some cases the generated 3D object can beretrieved and finalized without removal of transformed material and/orauxiliary features. Trimming may comprise ablating. Further processingmay comprise curing, baking, or annealing.

The methods, apparatuses, and systems provided herein can result in fastand efficient formation of 3D objects. In some cases, the 3D object canbe transported within at least about 120 min, 100 min, 80 min, 60 min,40 min, 30 min, 20 min, 10 min, or 5 min after the last layer of theobject hardens. In some cases, the 3D object can be transported withinany time between the above-mentioned values (e.g., from about 5 min toabout 120 min, from about 5 min to about 60 min, or from about 60 min toabout 120 min). The 3D object can be transported once it cools to atemperature of at most about 100° C., 90° C., 80° C., 70° C., 60° C.,50° C., 40° C., 30° C., 25° C., 20° C., 15° C., 10° C., or 5° C. The 3Dobject can be transported once it cools to a temperature value betweenthe above-mentioned temperature values (e.g., from about 5° C. to about100° C., from about 5° C. to about 40° C., or from about 15° C. to about40° C.). Transporting the 3D object can comprise packaging and/orlabeling the 3D object. In some cases, the 3D object can be transporteddirectly to a consumer.

Systems, apparatuses, and/or methods presented herein can facilitateformation of custom or stock 3D objects for a customer. A customer canbe an individual, a corporation, organization, government, non-profitorganization, company, hospital, medical practitioner, engineer,retailer, any other entity, or individual. The customer may be one thatis interested in receiving the 3D object and/or that ordered the 3Dobject. A customer can submit a request for formation of a 3D object.The customer can provide an item of value in exchange for the 3D object.The customer can provide a design or a 3D model for the 3D object. Thecustomer can provide the design in the form of a stereo lithography(STL) file. The customer can provide a design where the design can be adefinition of the shape and dimensions of the 3D object in any othernumerical or physical form. In some cases, the customer can provide a 3Dmodel, sketch, or image as a design of an object to be generated. Thedesign can be transformed in to instructions usable by the printingsystem to additively generate the 3D object. The customer can provide arequest to form the 3D object from a specific material or group ofmaterials (e.g., a material as described herein). In some cases, thedesign may not contain auxiliary features or marks of any past presenceof auxiliary support features.

The 3D object (e.g., solidified material) that is generated for thecustomer can have an average deviation value from the intendeddimensions of at most about 0.5 microns (μm), 1 μm, 3 μm, 10 μm, 30 μm,100 μm, or 300 μm. The deviation can be any value between theaforementioned values (e.g., from about 0.5 μm to about 300 μm, fromabout 10 μm to about 50 μm, from about 15 to about 85 μm, from about 5μm to about 45 μm, or from about 15 μm to about 35 μm). The 3D objectcan have a deviation from the intended dimensions in a specificdirection, according to the formula Dv+L/K_(Dv), wherein Dv is adeviation value, L is the length of the 3D object in a specificdirection, and K_(Dv) is a constant. Dv can have a value of at mostabout 300 μm, 200 μm, 100 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm, 5 μm, 1μm, or 0.5 μm. Dv can have a value of at least about 0.5 μm, 1 μm, 3 μm,5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 70 μm, 100 μm, or 300 μm. Dv can haveany value between the aforementioned values (e.g., from about 0.5 μm toabout 300 μm, from about 10 μm to about 50 μm, from about 15 μm to about85 μm, from about 5 μm to about 45 μm, or from about 15 μm to about 35μm). K_(dv) can have a value of at most about 3000, 2500, 2000, 1500,1000, or 500. K_(dv) can have a value of at least about 500, 1000, 1500,2000, 2500, or 3000. K_(dv) can have any value between theaforementioned values (e.g., from about 3000 to about 500, from about1000 to about 2500, from about 500 to about 2000, from about 1000 toabout 3000, or from about 1000 to about 2500). The intended dimensionscan be derived from a model design. The 3D part can have the statedaccuracy value immediately after its formation, without additionalprocessing (e.g., further processing) or manipulation. Receiving theorder for the object, formation of the object, and delivery of theobject to the customer can take at most about 7 days, 6 days, 5 days, 3days, 2 days, 1 day, 12 hours, 6 hours, 5 hours, 4 hours, 3 hours, 2hours, 1 hour, 30 min, 20 min, 10 min, 5 min, 1 min, 30 seconds, or 10seconds. In some cases, the 3D object can be additively generated in aperiod between any of the aforementioned time periods (e.g., from about10 seconds to about 7 days, from about 10 seconds to about 12 hours,from about 12 hours to about 7 days, or from about 12 hours to about 10minutes). The time can vary based on the physical characteristics of theobject, including the size and/or complexity of the object.

In some embodiments, the system and/or apparatus comprises at least onecontrolling system (e.g., comprising a controller). In some examples,the controller controls one or more of the components described herein.In some instances, at least two apparatuses are controlled by onecontroller. In some instances, each of at least two apparatuses has adifferent controller. The controller may comprise a computer-processingunit (e.g., at least one computer) coupled to any of the systems,apparatuses, and/or their respective components (e.g., the energysource(s)). The computer can be operatively coupled through a wiredand/or wireless connection. In some cases, the computer can be on boarda user device. A user device can be a laptop computer, desktop computer,tablet, smartphone, or another computing device. The controller can bein communication with a cloud computer system and/or a server. Thecontroller can be programmed to selectively direct the energy source(s)to apply energy to the at least a portion of the target surface at apower per unit area. The controller can be in communication with thescanner configured to articulate the energy source(s) to apply energy toat least a portion of the target surface at a power per unit area.

The controller may control the layer dispensing mechanism and/or any ofits components. The control may comprise controlling (e.g., directingand/or regulating) the speed (velocity) of movement of an apparatus orany of its components. The movement may be horizontal, vertical, and/orin an angle. The controller may control the cooling member (e.g.,external and/or internal). The control may be manual and/or automatic.The control may be programmed and/or be effectuated a whim. The controlmay be according to an algorithm. The algorithm may comprise a printingalgorithm, or motion control algorithm. The algorithm may take intoaccount the control-model of the 3D object.

FIG. 13 shows a schematic example of a (e.g., automatic) controller(e.g., a control system, or a first-controller) 1300 that is programmedor otherwise configured to facilitate formation of one or more 3Dobjects. In this example, the controller 1300 comprises asubordinate-controller 1340, at least one forming 3D object 1350, one ormore sensors (e.g. temperature sensor) 1360, one or more control-models1370 for the physical process of 3D printing and optionally at least onefeedback control loop (e.g., 1330, and 1333). The subordinate-controllermay be an internal-controller. The subordinate-controller can be asecond-controller as part of the first controller. Thesubordinate-controller (e.g., 1340) can be a linear controller. Thecontroller 1300 may be configured to control (e.g., in real time duringat least a portion of the 3D printing) a controllable propertycomprising: (i) an energy beam power (e.g., delivered to the materialbed), (ii) temperature at a position in the material bed (e.g., on theforming 3D object), (iii) energy beam speed, (iv) energy beam powerdensity, (v) energy beam dwell time, (vi) energy beam footprint (e.g.,on the exposed surface of the material bed), (vii) energy beam focus, or(viii) energy beam cross-section. The controllable property may be acontrol variable. The control may be to maintain a target parameter(e.g., temperature) of one or more forming 3D objects. The targetparameter may vary in time (e.g., in real time) and/or in location. Thelocation may comprise a location at the exposed surface of the materialbed. The location may comprise a location at the top surface of the(e.g., forming) 3D object. The target parameter may correlate to thecontrollable property. The (e.g., input) target parameter may vary intime and/or location in the material bed (e.g., on the forming 3Dobject). The subordinate-controller may receive a pre-determined powerper unit area (of the energy beam), temperature, and/or metrological(e.g., height) target value. For example, the subordinate-controller mayreceive a target parameter 1305 (e.g. temperature) to maintain at leastone characteristics of the forming 3D object (e.g., dimension in adirection, and/or temperature). In the example shown in FIG. 13, thecontroller receives three types of target inputs: (i) energy beam power1310 (which may be user defined), (ii) temperature (e.g., 1305), and(iii) geometry (e.g., 1335). The geometry may comprise geometricalobject pre-print correction. The geometric information may derive fromthe 3D object (or a correctively deviated (e.g., altered) modelthereof). The geometry may comprise geometric information of apreviously printed portion of the 3D object (e.g., comprising a localthickness below a given layer, local build angle, proximity to an edgeon a given layer, or proximity to layer boundaries). The geometry may bean input to the controller (e.g., via an open loop control scheme). Someof the target values may be used to form 3D printing instructions forgenerating the 3D object (e.g., 1350). The printing instructions may bedynamically adjusted in real time. The controller may monitor (e.g.,continuously) one or more signals from one or more sensors (e.g., 1360).For example, the controller may monitor the energy beam power,temperature of a position in the material bed, and/or metrology (e.g.,height) of a position in the material bed. The position in the materialbed may be of the forming 3D object. The monitor may be continuous ordiscontinuous. The monitor may be in real-time during the 3D printing.The monitor may be using the one or more sensors. The printinginstructions may be dynamically adjusted in real time (e.g., using thesignals from the one or more sensors). A variation between the targetparameter and the sensed parameter may be used to estimate an error inthe value of that parameter (e.g., 1320). The variation (e.g., error)may be used by the subordinate-controller (e.g., 1340) to adjust theprinting instructions. The controller may control (e.g., continuously)one or more parameters (e.g., in real time). The controller may usehistorical data (e.g., for the parameters). The historical data may beof previously printed 3D objects, or of previously printed layers of the3D object. The control-model may comprise free parameters which may beestimated using a characterization process. The characterization processmay be before, during (e.g., in real time), or after the 3D printing.The control-model may be wired to the controller. The control model canbe configured into the controller (e.g., before and/or during the 3Dprinting). Configured may comprise built, constructed, designed,patterned, or arranged. The hardware of the controller may comprise thecontrol-model. The control-model may be linear or non-linear. Forexample, the control-model may be non-linear. The control-model maycomprise linear or non-linear modes.

A control-model may predict and/or estimate one or more physicalparameters (e.g., 1371) of the forming 3D object (e.g., in real time).In some embodiments, the control-model is a reduced form of the 3D modelof the desired 3D object. In some embodiments, the control-model is asimplified 3D model compared to the complete 3D model of the desired 3Dobject. The physical parameters may comprise shape. For example, thecontrol-model may comprise the shape (e.g., geometry) of the 3D object.The control-model may be used to adjust the 3D printing. Thecontrol-model may comprise a simulation. The simulation may comprise animitation of a real-world process (e.g., 3D printing) over time. Thesimulation may comprise finite element analysis. For example, thecontrol-model may comprise a thermal and/or mechanical (e.g., elasticand/or plastic) simulation. For example, the control-model may comprisethermo-mechanical (e.g., thermo-elastic and/or thermos-plastic)simulation. The simulation may comprise the material(s) of the forming3D object (e.g., material(s) in the material bed). For example, thesimulation may comprise the material properties of the desired 3Dobject. The simulation and/or control-model may be adjusted (e.g., usingthe control loop) using one or more measured parameters. The simulationand/or control-model may be adjusted in real-time. The control-model mayoutput an estimation of the parameter. The simulation and/orcontrol-model may use an input from the one or more sensors (e.g.,power, temperature, and/or metrology sensors). The control-model cancomprise one or more free parameters. The one or more free parameterscan be optimized in real time (e.g., using one or more sensor signals).The controller may comprise an internal-state-system that provides anestimate of an internal state of the 3D printer and/or 3D printing. Theinternal state can be derived from one or more measurements of thecontrol variable and/or input parameters. The internal-state-system maybe implemented using a computer. The internal-state-system may comprisea state-observer. The controller may comprise a state-observer. Thecontrol-model can be a state-observer-model. The controller may comprisea reconfigurable firm-ware (e.g., flash memory). The controller maycomprise a microprocessor. The controller may comprise a (e.g.,programmable and/or reconfigurable) circuit. The estimated parameter maybe compared (e.g., 1325) with the measured parameter (e.g., 1373). Thecomparison may be used to alter (e.g., 1372) the control-model. Thecontrol-model may dynamically be adjusted in real time. The simulationmay be dynamically adjusted in real-time. The prediction of theparameter may be done offline (e.g. predetermined) and/or in real-time(e.g., during the 3D printing). The control-model may receive the sensedparameter(s) value(s). The control-model may use the sensed parameter(s)value(s) for a prediction and/or adjustment of at least one targetparameter. For example, the control-model may use geometric information(e.g., 1335) associated with the requested and/or forming 3D object. Thecontrol-model may set up a feedback control loop (e.g., 1330) to adjustone or more target parameters in order to achieve convergence (e.g.,with the desired 3D object). The feedback loop(s) control may compriseone or more comparisons with an input parameter (e.g., 1320) and/orthreshold value (e.g., 1380). Real time may be during formation of atleast one: 3D object, a layer within the 3D object, dwell time of anenergy beam along a path, and dwell time of an energy beam along a hatchline dwell time of an energy beam forming a melt pool. The one or moreforming 3D objects can be generated (e.g., substantially)simultaneously, or sequentially. The one or more 3D objects can beformed in a (e.g., single) material bed.

The subordinate-controller 1340 may output one or more parameters aspart of the 3D printing instructions. The output of thesubordinate-controller may be based on one or more parameter input(e.g., of a different type). For example, the subordinate-controller mayreceive a temperature input and output a power parameter. The outputparameter may be compared with the same type of parameter that wasinput. For example, the output power parameter, may be compared with(e.g., 1315) a power input to generate the printing instructions for theportion of the 3D object. The comparison may be a dynamic comparison inreal time. The comparison may be prior or subsequent to the 3D printing.

The controller may be implemented in a processor hardware (e.g., GPU,CPU, or FPGA). The controller may have a band width of at least about 1Kilo-Hertz (KHz), 5 KHz, 10 KHz, 20 KHz, 30 KHz, 30 KHz, 40 KHz, 50 KHz,60 KHz, 70 KHz, or 80 KHz. The controller may have a band width betweenany of the aforementioned values (e.g., from about 1 KHz to about 80KHz, from about 1 KHz to about 50 KHz, from about 10 KHz, to about 50KHz, from about 30 KHz to about 60 KHz, or from about 50 KHz to about 80KHz).

The systems, methods, and/or apparatuses disclosed herein may comprisereceiving a request for a 3D object (e.g., from a customer). The requestcan include a 3D model (e.g., CAD) of the desired 3D object.Alternatively or additionally, a 3D model of the desired 3D object maybe generated. The 3D model may be used to generate 3D printinginstructions. The 3D printing instructions may exclude the 3D model. The3D printing instructions may be based on the 3D model. The 3D printinginstructions may take the 3D model into account. The 3D printinginstructions may be based on simulations (e.g., as disclosed herein). Insome embodiments, the 3D printing instructions may use more than one 3Dmodel. The 3D printing instructions may comprise using an algorithm(e.g., embedded in a software) that takes into account the 3D model. Thealgorithm may comprise the simulation. The algorithm may take intoaccount a deviation in shape (e.g., geometry) from the model. Thedeviation may be a structural (e.g., geometrical) deviation. In someembodiments, the 3D model may comprise feedback or feed forward controlsbased on an algorithm (e.g., comprised in a script). The algorithm maybe embedded in a script. In some examples, a script is a languagespecific computer readable media (e.g., software) implementation of thealgorithm. For example, the control-model may combine feedback andfeed-forward controls based on an algorithm (e.g., FIG. 13). Thedeviation may be a corrective deviation. The corrective (structural)deviation may be such that at least a portion of the 3D object isprinted according to a deviation from the 3D model of the desired 3Dobject; and upon hardening, the at least a portion of the 3D object(and/or the entire 3D object) will not (e.g., substantially) deviatefrom the 3D model of the desired 3D object. The deviation may span oneor more layers of the 3D object. For example, the deviation in shape(e.g., in geometry) may span a multiplicity of layers. At times, atleast a portion of the layer (e.g., slice thereof) is deviated from the3D model. A slice is a virtual reality representation of the layer ofthe 3D object in the 3D model. The 3D model is a virtual realityrepresentation of a desired 3D object. Virtual reality may comprisecomputerized, or computer generated. At least the first derivative ofthe difference between the deviated model and the requested model of the3D object, may be continuous (e.g., smooth). At least the firstderivative can be smooth (e.g., continuous). The at least the firstderivative can be a plurality of derivatives. The plurality ofderivatives can comprise at least the 2^(nd), 3^(rd), 4^(th), 5^(th),6^(th), 7^(th), 8^(th), 9^(th), or 10^(th) derivative. At times, atleast the first degree gradient of the geometrical deviation field issmooth (e.g., continuous). The geometrical deviation field can include adifference between the deviated model and the requested model of the 3Dobject. At times, the at least the first derivative may be infinitelysmooth. At times, all the derivatives are continuous. At times, the atleast the first degree comprises a plurality of degrees. The deviationmay exclude inserting one or more kinks in the 3D object. The smooth oneor more derivatives is of the deviation from the 3D object (e.g., todifferentiate from a structural derivative(s) of the 3D object). Thederivative and/or gradient may be sensitive to the change in geometrybetween the desired 3D object, and the deformed 3D object. The deviationmay be a corrective deviation that at least in part compensates fordeformation during the 3D printing. The deformation may be anaccumulated deformation. The accumulated deformation may be a residuallyaccumulated deformation during the 3D printing. Such corrective (e.g.,compensatory) deviation is termed herein as “object pre-printcorrection.” The deviation may be an adjustment or alteration

In some embodiments, the printed deviation is cancelled out due todeformation of the 3D object (or portion thereof) during the 3Dprinting. In some embodiments, the algorithm used to form the 3Dprinting instructions excludes a feedback control loop (e.g., closedloop). In some embodiments, 3D printing instructions may exclude takinginto account metrology and/or temperature measurements of the generated3D object (e.g., measurements of the 3D object) or parts thereof. Insome embodiments, 3D printing instructions may include taking intoaccount metrology and/or temperature measurements of the generated 3Dobject (e.g., measurements of the 3D object) or parts thereof. In someembodiments, the 3D printing instructions may comprise an open loopcontrol. The algorithm may use historical (e.g., empirical) data. Theempirical data may be of characteristic structures (e.g., that areincluded in the desired 3D object). The characteristic structures may be(e.g., substantially) similar to at least portions of the 3D object. Theempirical data may be previously obtained. In some embodiments, thealgorithm may comprise a feed forward control loop. The feed forwardcontrol loop may override one or more model parameters (for example,measurements and/or corrections). In some embodiments, the algorithm maycomprise feed forward control loop (e.g., elements thereof), feedbackcontrol loop (e.g., elements thereof), or a combination of feed forwardand feedback control loop (e.g., elements thereof). In some embodiments,the algorithm may use a theoretical model. The algorithm may use a modelof energy flow (e.g., heat flow). At times, the algorithm comprisesthermal, or mechanical algorithm. The mechanical algorithm may compriseelastic or plastic algorithm. In some examples, the generation of the 3Dobject using a (e.g., structurally) altered 3D model may exclude aniterative process. In some examples, the generation of the 3D objectusing an altered 3D model may include an iterative process. Thegeneration of the 3D object may not involve an alteration of the 3Dmodel (e.g., CAD), but rather generate a new set of 3D printinginstructions. In some embodiments, the algorithm is used to alter 3Dprinting instructions received by at least one of the componentsinvolved in the 3D printing process (e.g., energy beam). In someembodiments, the algorithm does not (e.g., structurally) alter the 3Dmodel. The algorithm may comprise a generic approach to printing adesired 3D object (or portions thereof.) In some embodiments, thealgorithm is not based on at least one of (i) altering 3D printinginstructions that are based on printing the desired 3D object, (ii)measuring errors in the printed 3D object, and (iii) revising theprinting instructions. In some embodiments, the algorithm is not basedon an iterative process that takes into account the desired and printed3D object (e.g., in real-time). The algorithm may be based on anestimation of one or more errors (e.g., deformation errors) during theprinting of the desired 3D object. The algorithm may comprise correctingthe estimated errors through the generation of respective 3D printinginstructions that take into account the anticipated errors. In someexamples, the algorithm comprises circumventing the estimated errorsthrough the generation of respective 3D printing instructions. Thecorrection of errors may be prior and/or during the 3D printing (e.g.,in real-time). In this manner, the algorithm may circumvent generationof errors (e.g., structural errors such as deformations). The algorithmmay be based on an estimation of one or more errors (e.g., before orduring the printing of the desired 3D object) and correcting themthrough the generation of respective 3D printing instructions that takeinto account the anticipated errors, and thus circumvent the generationof the errors. The error may comprise the deviation from the 3D model ofthe desired 3D object. The estimation may be based on simulation,modeling, and/or historical data (e.g., of representative 3D structuresor 3D structure segments). In some embodiments, the error(s) may not beanticipated (e.g. in real-time). In some embodiments, one or moresensors operatively coupled to the at least one controllably monitor theforming 3D object (e.g., and detect errors). The 3D printinginstructions may be altered in real time to correct the detected errors.FIG. 12 shows an example of a flow chart representing at least a portionof the 3D printing process operations that are executed by a 3D printingsystem and/or apparatus described herein. The desired 3D object isrequested in operation 1201. A 3D model is provided or generated inoperation 1202. Operation 1204 illustrates the generation of printinginstruction(s) for the 3D object, in which at least one of the 3D modeland the algorithm is utilized. In this example, the 3D object issubsequently generated using the printing instruction(s) in operation1205. In this example, the desired 3D object is delivered in operation1206. Arrow 1207 designates the direction of the execution of theoperations from operation 1201 to operation 1206. The absence of backfeeding arrow represents the lack of a feedback loop control.

In some embodiments, the controller comprises a processing unit. Theprocessing unit may be central. The processing unit may comprise acentral processing unit (herein “CPU”). The controller (e.g., comprisinga computer system) may be programmed to implement methods of thedisclosure. The controller may control at least one component of thesystems and/or apparatuses disclosed herein. FIG. 14 is a schematicexample of a computer system 1400 that is programmed or otherwiseconfigured to facilitate the formation of a 3D object according to themethods provided herein. The computer system 1400 can control (e.g.,direct and/or regulate) various features of printing methods,apparatuses and systems of the present disclosure, such as, for example,regulating force, translation, heating, cooling and/or maintaining thetemperature of a material bed, process parameters (e.g., chamberpressure), energy beam characteristic, scanning route of the energysource, position and/or temperature of the cooling member(s),application of the amount of energy emitted to a selected location, orany combination thereof. The computer system can be part of, or be incommunication with, a printing system or apparatus, such as a 3Dprinting system or apparatus of the present disclosure. The computer maybe coupled to one or more mechanisms disclosed herein, and/or any partsthereof. For example, the computer may be coupled to one or moresensors, valves, switches, motors, pumps, or any combination thereof.

The computer system 1400 can include a processing unit 1406 (also“processor,” “computer” and “computer processor” used herein). Thecomputer system may include memory or memory location 1402 (e.g.,random-access memory, read-only memory, flash memory), electronicstorage unit 1404 (e.g., hard disk), communication interface 1403 (e.g.,network adapter) for communicating with one or more other systems, andperipheral devices 1405, such as cache, other memory, data storageand/or electronic display adapters. In some examples, the memory 1402,storage unit 1404, interface 1403, and peripheral devices 1405 are incommunication with the processing unit 1406 through a communication bus(solid lines), such as a motherboard. The storage unit can be a datastorage unit (or data repository) for storing data. The computer systemcan be operatively coupled to a computer network (“network”) 1401 withthe aid of the communication interface. The network can be the Internet,an Internet and/or extranet, or an intranet and/or extranet that is incommunication with the Internet. The network in some cases is atelecommunication and/or data network. The network can include one ormore computer servers, which can enable distributed computing, such ascloud computing. The network, in some cases with the aid of the computersystem, can implement a peer-to-peer network, which may enable devicescoupled to the computer system to behave as a client or a server.

The processing unit can execute a sequence of machine-readableinstructions, which can be embodied in a program or software. Theinstructions may be stored in a memory location, such as the memory1402. The instructions can be directed to the processing unit, which cansubsequently program or otherwise configure the processing unit toimplement methods of the present disclosure. Examples of operationsperformed by the processing unit can include fetch, decode, execute, orwrite back. The processing unit may interpret and/or executeinstructions. The processor may include a microprocessor, dataprocessor, central processing unit (CPU), graphical processing unit(GPU), system-on-chip (SOC), co-processor, network processor,application specific integrated circuit (ASIC), application specificinstruction-set processor (ASIPs), controller, programmable logic device(PLD), chipset, field programmable gate array (FPGA), or any combinationthereof. The processing unit can be part of a circuit, such as anintegrated circuit. One or more other components of the system 1400 canbe included in the circuit.

The storage unit 1404 can store files, such as drivers, libraries andsaved programs. The storage unit can store user data, e.g., userpreferences and user programs. The computer system in some cases caninclude one or more additional data storage units that are external tothe computer system, such as located on a remote server that is incommunication with the computer system through an intranet or theInternet.

The computer system can communicate with one or more remote computersystems through the network. For instance, the computer system cancommunicate with a remote computer system of a user (e.g., operator).Examples of remote computer systems include personal computers (e.g.,portable PC), slate or tablet PC's (e.g., Apple® iPad, Samsung® GalaxyTab), telephones, Smart phones (e.g., Apple® iPhone, Android-enableddevice, Blackberry®), or personal digital assistants. The user canaccess the computer system via the network.

Methods as described herein can be implemented by way of machine (e.g.,computer processor) executable code stored on an electronic storagelocation of the computer system, such as, for example, on the memory1402 or electronic storage unit 1404. The machine executable ormachine-readable code can be provided in the form of software. Duringuse, the processor 1406 can execute the code. In some cases, the codecan be retrieved from the storage unit and stored on the memory forready access by the processor. In some situations, the electronicstorage unit can be precluded, and machine-executable instructions arestored on memory.

The code can be pre-compiled and configured for use with a machine havea processer adapted to execute the code, or can be compiled duringruntime. The code can be supplied in a programming language that can beselected to enable the code to execute in a pre-compiled or as-compiledfashion.

The processing unit may include one or more cores. The computer systemmay comprise a single core processor, multi core processor, or aplurality of processors for parallel processing. The processing unit maycomprise one or more central processing unit (CPU) and/or a graphicprocessing unit (GPU). The multiple cores may be disposed in a physicalunit (e.g., Central Processing Unit, or Graphic Processing Unit). Theprocessing unit may include one or more processing units. The physicalunit may be a single physical unit. The physical unit may be a die. Thephysical unit may comprise cache coherency circuitry. The multiple coresmay be disposed in close proximity. The physical unit may comprise anintegrated circuit chip. The integrated circuit chip may comprise one ormore transistors. The integrated circuit chip may comprise at least 0.2billion transistors (BT), 0.5 BT, 1BT, 2 BT, 3 BT, 5 BT, 6 BT, 7 BT, 8BT, 9 BT, 10 BT, 15 BT, 20 BT, 25 BT, 30 BT, 40 BT, or 50 BT. Theintegrated circuit chip may comprise any number of transistors betweenthe afore-mentioned numbers (e.g., from about 0.2 BT to about 100 BT,from about 1 BT to about 8 BT, from about 8 BT to about 40 BT, or fromabout 40 BT to about 100 BT). The integrated circuit chip may have anarea of at most 50 mm², 60 mm², 70 mm², 80 mm², 90 mm², 100 mm², 200mm², 300 mm², 400 mm², 500 mm², 600 mm², 700 mm², or 800 mm². Theintegrated circuit chip may have an area of any value between theafore-mentioned values (e.g., from about 50 mm² to about 800 mm², fromabout 50 mm² to about 500 mm², or from about 500 mm² to about 800 mm²).The close proximity may allow substantial preservation of communicationsignals that travel between the cores. The close proximity may diminishcommunication signal degradation. A core as understood herein is acomputing component having independent central processing capabilities.The computing system may comprise a multiplicity of cores, which aredisposed on a single computing component. The multiplicity of cores mayinclude two or more independent central processing units. Theindependent central processing units may constitute a unit that read andexecute program instructions. The multiplicity of cores can be parallelcores. The multiplicity of cores can function in parallel. Themultiplicity of cores may include at least 2, 10, 40, 100, 400, 1000,2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, or 10000 cores. Themultiplicity of cores may include cores of any number between theafore-mentioned numbers (e.g., from 2 to 40000, from 2 to 400, from 400to 4000, from 2000 to 4000, or from 4000 to 10000 cores). The cores maycommunicate with each other via on chip communication networks; and/orcontrol, data and communication channels. The processor may comprise lowlatency in data transfer (e.g., from one core to another). Latency mayrefer to the time delay between the cause and the effect of a physicalchange in the processor (e.g., a signal). Latency may refer to the timeelapsed from the source (e.g., first core) sending a packet to thedestination (e.g., second core) receiving it (also referred as two pointlatency). One point latency may refer to the time elapsed from thesource (e.g., first core) sending a packet (e.g., signal) to thedestination (e.g., second core) receiving it, and the designationsending a packet back to the source (e.g., the packet making a roundtrip). The latency may be sufficiently low to allow a high number offloating point operations per second (FLOPS). The number of FLOPS may beat least about 1 Tera Flops (T-FLOPS), 2 T-FLOPS, 3 T-FLOPS, 5 T-FLOPS,6 T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9 T-FLOPS, or 10 T-FLOPS. The number offlops may be at most about 5 T-FLOPS, 6 T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9T-FLOPS, 10 T-FLOPS, 20 T-FLOPS, or 30 T-FLOPS. The number of FLOPS maybe any value between the afore-mentioned values (e.g., from about 1T-FLOP to about 30 T-FLOP, from about 4 T-FLOPS to about 10 T-FLOPS,from about 1 T-FLOPS to about 10 T-FLOPS, or from about 10 T-FLOPS toabout 30 T-FLOPS. The FLOPS can be measured according to a benchmark.The benchmark may be a HPC Challenge Benchmark. The benchmark maycomprise mathematical operations (e.g., equation calculation such aslinear equations), graphical operations (e.g., rendering), orencryption/decryption benchmark. The benchmark may comprise a HighPerformance LINPACK, matrix multiplication (e.g., DGEMM), sustainedmemory bandwidth to/from memory (e.g., STREAM), array transposing ratemeasurement (e.g., PTRANS), RandomAccess, rate of Fast Fourier Transform(e.g., on a large one-dimensional vector using the generalizedCooley-Tukey algorithm), or Communication Bandwidth and Latency (e.g.,MPI-centric performance measurements based on the effectivebandwidth/latency benchmark). LINPACK refers to a software library forperforming numerical linear algebra on a digital computer. DGEMM refersto double precision general matrix multiplication. STREAM convention maysum the amount of data that an application code explicitly reads and theamount of data that the application code explicitly writes. PTRANS maymeasure the rate at which the system can transpose a large array (e.g.,matrix). MPI refers to Message Passing Interface.

The computer system may include hyper-threading technology. The computersystem may include a chip processor with integrated transform, lighting,triangle setup, triangle clipping, rendering engine, or any combinationthereof. The rendering engine may be capable of processing at leastabout 10 million polygons per second. The rendering engines may becapable of processing at least about 10 million calculations per second.As an example, the GPU may include a GPU by Nvidia, ATI Technologies, S3Graphics, Advanced Micro Devices (AMD), or Matrox. The processing unitmay be able to process algorithms comprising a matrix or a vector. Thecore may comprise a complex instruction set computing core (CISC), orreduced instruction set computing (RISC).

The computer system may include one or more electronic chips that isreprogrammable (e.g., field programmable gate array (FPGA)). Forexample, the FPGA may comprise Tabula, Lattice, Altera, or Xilinx FPGA.The electronic chips may comprise one or more programmable logic blocks(e.g., an array). The logic blocks may compute combinational functions,logic gates, or any combination thereof. The computer system may includecustom hardware. The custom hardware may comprise an algorithm. Thecomputer system may include custom software that may comprise analgorithm.

The computer system may include configurable computing, partiallyreconfigurable computing, reconfigurable computing, or any combinationthereof. The computer system may include a FPGA. The computer system mayinclude an integrated circuit that performs the algorithm. For example,the reconfigurable computing system may comprise FPGA, CPU, GPU, ormulti-core microprocessors. The reconfigurable computing system maycomprise a High-Performance Reconfigurable Computing architecture(HPRC). The partially reconfigurable computing may include module-basedpartial reconfiguration, or difference-based partial reconfiguration.

The computing system may include an integrated circuit that performs thealgorithm (e.g., control algorithm). The computing system may includeapplication specific software that performs the algorithm. The physicalunit (e.g., the cache coherency circuitry within) may have a clock timeof at least about 0.1 Gigabits per second (Gbit/s), 0.5 Gbit/s, 1Gbit/s, 2 Gbit/s, 5 Gbit/s, 6 Gbit/s, 7 Gbit/s, 8 Gbit/s, 9 Gbit/s, 10Gbit/s, or 50 Gbit/s. The physical unit may have a clock time of anyvalue between the afore-mentioned values (e.g., from about 0.1 Gbit/s toabout 50 Gbit/s, or from about 5 Gbit/s to about 10 Gbit/s). Thephysical unit may produce the algorithm output in at most 0.1microsecond (μs), 1 μs, 10 μs, 100 μs, or 1 millisecond (ms). Thephysical unit may produce the algorithm output in any time between theabove mentioned times (e.g., from about 0.1 μs, to about 1 ms, fromabout 0.1 μs, to about 100 μs, or from about 0.1 μs to about 10 μs). Insome instances, the controller may use calculations, real timemeasurements, or any combination thereof to control the energy beam(s).In some instances, the real time measurements (e.g., temperaturemeasurements) may provide input at a rate of at least about 0.1 KHz, 1KHz, 10 KHz, 100 KHz, 1000 KHz, or 10000 KHz). In some instances, thereal time measurements may provide input at a rate between any of theabove-mentioned rates (e.g., from about 0.1 KHz to about 10000 KHz, fromabout 0.1 KHz to about 1000 KHz, or from about 1000 KHz to about 10000KHz). The memory bandwidth of the processing unit may be at least about1 gigabytes per second (Gbytes/s), 10 Gbytes/s, 100 Gbytes/s, 200Gbytes/s, 300 Gbytes/s, 400 Gbytes/s, 500 Gbytes/s, 600 Gbytes/s, 700Gbytes/s, 800 Gbytes/s, 900 Gbytes/s, or 1000 Gbytes/s. The memorybandwidth of the processing unit may any value between theaforementioned values (e.g., from about 1 Gbytes/s to about 1000Gbytes/s, from about 100 Gbytes/s to about 500 Gbytes/s, from about 500Gbytes/s to about 1000 Gbytes/s, or from about 200 Gbytes/s to about 400Gbytes/s).

Aspects of the systems, apparatuses, and/or methods provided herein,such as the computer system, can be embodied in programming. Variousaspects of the technology may be thought of as “product,” “object,” or“articles of manufacture” typically in the form of machine (orprocessor) executable code and/or associated data that is carried on orembodied in a type of machine-readable medium. Machine-executable codecan be stored on an electronic storage unit, such memory (e.g.,read-only memory, random-access memory, flash memory) or a hard disk.The storage may comprise non-volatile storage media. “Storage” typemedia can include any or all of the tangible memory of the computers,processors or the like, or associated modules thereof, such as varioussemiconductor memories, tape drives, disk drives, external drives, andthe like, which may provide non-transitory storage at any time for thesoftware programming.

The memory may comprise a random access memory (RAM), dynamic randomaccess memory (DRAM), static random access memory (SRAM), synchronousdynamic random access memory (SDRAM), ferroelectric random access memory(FRAM), read only memory (ROM), programmable read only memory (PROM),erasable programmable read only memory (EPROM), electrically erasableprogrammable read only memory (EEPROM), a flash memory, or anycombination thereof. The flash memory may comprise a negative-AND (NAND)or NOR logic gates. The storage may include a hard disk (e.g., amagnetic disk, an optical disk, a magneto-optic disk, a solid statedisk, etc.), a compact disc (CD), a digital versatile disc (DVD), afloppy disk, a cartridge, a magnetic tape, and/or another type ofcomputer-readable medium, along with a corresponding drive.

All or portions of the software may at times be communicated through theInternet or various other telecommunication networks. Suchcommunications, for example, may enable loading of the software from onecomputer or processor into another, for example, from a managementserver or host computer into the computer platform of an applicationserver. Thus, another type of media that may bear the software elementsincludes optical, electrical and electromagnetic waves, such as usedacross physical interfaces between local devices, through wired andoptical landline networks and over various air-links. The physicalelements that carry such waves, such as wired or wireless links, opticallinks, or the like, also may be considered as media bearing thesoftware. As used herein, unless restricted to non-transitory, tangible“storage” media, terms such as computer or machine “readable medium”refer to any medium that participates in providing instructions to aprocessor for execution.

Hence, a machine-readable medium, such as computer-executable code, maytake many forms, including but not limited to, a tangible storagemedium, a carrier wave medium, or physical transmission medium.Non-volatile storage media include, for example, optical or magneticdisks, such as any of the storage devices in any computer(s) or thelike, such as may be used to implement the databases, etc. shown in thedrawings. Volatile storage media include dynamic memory, such as mainmemory of such a computer platform. Tangible transmission media includecoaxial cables, wire (e.g., copper wire), and/or fiber optics, includingthe wires that comprise a bus within a computer system. Carrier-wavetransmission media may take the form of electric or electromagneticsignals, or acoustic or light waves such as those generated during radiofrequency (RF) and infrared (IR) data communications. Common forms ofcomputer-readable media therefore include for example: a floppy disk, aflexible disk, hard disk, magnetic tape, any other magnetic medium, aCD-ROM, DVD or DVD-ROM, any other optical medium, punch cards papertape, any other physical storage medium with patterns of holes, a RAM, aROM, a PROM and EPROM, a FLASH-EPROM, any other memory chip orcartridge, a carrier wave transporting data or instructions, cables orlinks transporting such a carrier wave, or any other medium from which acomputer may read programming code and/or data. The memory and/orstorage may comprise a storing device external to and/or removable fromdevice, such as a Universal Serial Bus (USB) memory stick, or a harddisk. Many of these forms of computer readable media may be involved incarrying one or more sequences of one or more instructions to aprocessor for execution.

The computer system can include or be in communication with anelectronic display that comprises a user interface (UI) for providing,for example, a model design or graphical representation of a 3D objectto be printed. Examples of UI's include, without limitation, a graphicaluser interface (GUI) and web-based user interface. The computer systemcan monitor and/or control various aspects of the 3D printing system.The control may be manual and/or programmed. The control may rely onfeedback mechanisms that have been pre-programmed. The feedbackmechanisms may rely on input from sensors (described herein) that areconnected to the control unit (e.g., control system. E.g., computer).The computer system may store historical data concerning various aspectsof the operation of the 3D printing system. The historical data may beretrieved at predetermined times and/or at a whim. The historical datamay be accessed by an operator and/or by a user. The historical and/oroperative data may be provided in an output unit such as a display unit.The output unit (e.g., monitor) may output various parameters of the 3Dprinting system (as described herein) in real time or in a delayed time.The output unit may output the current 3D printed object, the ordered 3Dprinted object, or both. The output unit may output the printingprogress of the 3D printed object. The output unit may output at leastone of the total time, time remaining, and time expanded on printing the3D object. The output unit may output (e.g., display, voice, and/orprint) the status of sensors, their reading, and/or time for theircalibration or maintenance. The output unit may output the type ofmaterial(s) used and various characteristics of the material(s) such astemperature and flowability of the pre-transformed material. The outputunit may output the amount of oxygen, water, and pressure in theprinting chamber (i.e., the chamber where the 3D object is beingprinted). The computer may generate a report comprising variousparameters of the 3D printing system, method, and or objects atpredetermined time(s), on a request (e.g., from an operator), and/or ata whim. The output unit may comprise a screen, printer, or speaker. Thecontroller may provide a report. The report may comprise any itemsrecited as optionally output by the output unit.

The system and/or apparatus described herein (e.g., controller) and/orany of their components may comprise an output and/or an input device.The input device may comprise a keyboard, touch pad, or microphone. Theoutput device may be a sensory output device. The output device mayinclude a visual, tactile, or audio device. The audio device may includea loudspeaker. The visual output device may include a screen and/or aprinted hard copy (e.g., paper). The output device may include aprinter. The input device may include a camera, a microphone, akeyboard, or a touch screen. The system and/or apparatus describedherein and/or any of their components may comprise Bluetooth technology.The system and/or apparatus described herein and/or any of theircomponents may comprise an electronic circuit. The system and/orapparatus described herein and/or any of their components may comprise acommunication port. The communication port may be a serial port or aparallel port. The communication port may be a Universal Serial Bus port(i.e., USB). The system and/or apparatus described herein (e.g.,controller) and/or any of their components may comprise USB ports. TheUSB can be micro or mini USB. The USB port may relate to device classescomprising 00h, 01h, 02h, 03h, 05h, 06h, 07h, 08h, 09h, 0Ah, 0Bh, 0Dh,0Eh, 0Fh, 10h, 11h, DCh, E0h, EFh, FEh, or FFh. The system and/orapparatus described herein and/or any of their components may comprise aplug and/or a socket (e.g., electrical, AC power, DC power). The systemand/or apparatus described herein and/or any of their components maycomprise an adapter (e.g., AC and/or DC power adapter). The systemand/or apparatus described herein and/or any of their components maycomprise a power connector. The power connector can be an electricalpower connector. The power connector may comprise a magnetically coupled(e.g., attached) power connector. The power connector can be a dockconnector. The connector can be a data and power connector. Theconnector may comprise pins. The connector may comprise at least 10, 15,18, 20, 22, 24, 26, 28, 30, 40, 42, 45, 50, 55, 80, or 100 pins.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. It is not intendedthat the invention be limited by the specific examples provided withinthe specification. While the invention has been described with referenceto the aforementioned specification, the descriptions and illustrationsof the embodiments herein are not meant to be construed in a limitingsense. Numerous variations, changes, and substitutions will now occur tothose skilled in the art without departing from the invention.Furthermore, it shall be understood that all aspects of the inventionare not limited to the specific depictions, configurations, or relativeproportions set forth herein which depend upon a variety of conditionsand variables. It should be understood that various alternatives to theembodiments of the invention described herein may be employed inpracticing the invention. It is therefore contemplated that theinvention shall also cover any such alternatives, modifications,variations, or equivalents. It is intended that the following claimsdefine the scope of the invention and that methods and structures withinthe scope of these claims and their equivalents be covered thereby.

What is claimed is:
 1. A system for forming at least onethree-dimensional object, comprising: (a) an energy beam that transformsat least a portion of a material bed to a transformed material; and (b)a controller comprising a control-model that is related to a requestedthree-dimensional object, which control-model is configured in thecontroller, which controller is operative coupled to the energy beam andis programmed to direct the energy beam to transform the at least aportion of the material bed to form the at least one three-dimensionalobject using the control-model.
 2. The system of claim 1, wherein thecontrol-model is adjusted in real time during the forming of the atleast one three-dimensional object.
 3. The method of claim 2, whereinreal time is during a dwell time of the energy beam along a hatch lineforming a melt pool.
 4. The method of claim 1, wherein the parametercomprises a temperature, height, or power density.
 5. The system ofclaim 1, wherein the at least one three-dimensional object is aplurality of three-dimensional objects.
 6. The system of claim 5,wherein the plurality of three-dimensional objects is formed in the samematerial bed.
 7. The system of claim 5, wherein the plurality ofthree-dimensional objects is formed in parallel.
 8. The system of claim1, wherein the controller comprises a closed loop or open loop control.9. The system of claim 1, wherein the controller comprises a feedback orfeed-forward control.
 10. The system of claim 1, wherein thecontrol-model comprises one or more free parameters that are optimizedin real time during the forming of the at least one three-dimensionalobject.
 11. The system of claim 1, wherein the controller comprises aninternal-state-system that provides an estimate of an internal state ofthe forming of the at least one three-dimensional object.
 12. The systemof claim 11, wherein the internal state is derived from one or moremeasurements comprising a measurement of the control variable or ameasurement of the input parameters.
 13. The system of claim 11, whereinthe internal-state-system comprises a state-observer.
 14. The system ofclaim 1, wherein the control-model comprises a state-observer-model. 15.The system of claim 1, wherein the controller comprises a graphicalprocessing unit (GPU), system-on-chip (SOC), application specificintegrated circuit (ASIC), application specific instruction-setprocessor (ASIPs), programmable logic device (PLD), or fieldprogrammable gate array (FPGA).
 16. The system of claim 1, wherein thethree-dimensional object is substantially similar to the requestedthree-dimensional object, wherein substantially is relative to theintended purpose of the three-dimensional object.
 17. A method forforming a three-dimensional object, comprising: (a) transforming aportion of a material bed with an energy beam to form at least a portionof the three-dimensional object; and (b) controlling in real time atleast one characteristics of the energy beam with a controllercomprising a control-model related to a requested three-dimensionalobject, which control-model is configured in the controller, wherein thethree-dimensional object is substantially similar to the requestedthree-dimensional object.
 18. The method of claim 17, wherein thecontrol-model is adjusted in real time during the forming of thethree-dimensional object.
 19. The method of claim 17, wherein real timeis during a dwell time of the energy beam along a hatch line forming amelt pool.
 20. The method of claim 17, wherein the controlling uses aprocessor comprising at least 3 Tera floating point operations persecond, according to a benchmark.
 21. The method of claim 17, furthercomprising adjusting the at least one characteristics of the energy beamand repeating (a) to (b).
 22. The method of claim 17, wherein the closedloop control uses at least one threshold value.
 23. The method of claim17, wherein the control-model comprises a simplified model relative tothe requested model of the three-dimensional object.
 24. The method ofclaim 17, wherein substantially is relative to the intended purpose ofthe three-dimensional object.
 25. The method of claim 17, wherein thecontrol-model comprises a state-observer-model.
 26. The method of claim17, wherein the control-model comprises a simulation.
 27. The method ofclaim 26, wherein the simulation comprises a temperature or mechanicalsimulation of the three-dimensional printing.
 28. The method of claim26, wherein the simulation comprises a material property of thethree-dimensional object.
 29. The method of claim 26, wherein thesimulation comprises a geometry of the three-dimensional object.
 30. Themethod of claim 26, wherein the control-model is dynamically adjusted inthe real time during the forming of the three-dimensional object.